Oracle® Database Gateway for Sybase · PDF fileThis manual describes the Oracle Database...

Oracle® Database Gateway for SybaseUser’s Guide

12c Release 1 (12.1)

E17932-04

April 2013

Oracle Database Gateway for Sybase User's Guide, 12c Release 1 (12.1)

E17932-04

Copyright © 2002, 2013, Oracle and/or its affiliates. All rights reserved.

Primary Author: Maitreyee Chaliha

Contributor: Vira Goorah, Juan Pablo Ahues-Vasquez, Peter Castro, Charles Benet, Peter Wong, andGovind Lakkoju

Contributor: The Oracle Database 12c documentation is dedicated to Mark Townsend, who was aninspiration to all who worked on this release.

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iii

Contents

List of Tables

Preface ................................................................................................................................................................ ix

Audience...................................................................................................................................................... ixDocumentation Accessibility .................................................................................................................... ixRelated Documents ..................................................................................................................................... xConventions ................................................................................................................................................. x

1 Introduction

Overview .................................................................................................................................................... 1-1Heterogeneous Services Technology.................................................................................................... 1-1Oracle Database Gateways ..................................................................................................................... 1-2

2 Sybase Gateway Features and Restrictions

Using the Pass-Through Feature ........................................................................................................... 2-1Executing Stored Procedures and Functions....................................................................................... 2-2

Return Values and Stored Procedures ............................................................................................ 2-2Result Sets and Stored Procedures .................................................................................................. 2-3

OCI Program Fetching from Result Sets in Sequential Mode .............................................. 2-4PL/SQL Program Fetching from Result Sets in Sequential Mode....................................... 2-5

CHAR Semantics ...................................................................................................................................... 2-6Multi-byte Character Sets Ratio Suppression .................................................................................... 2-6IPv6 Support.............................................................................................................................................. 2-6Gateway Session IDLE Timeout ........................................................................................................... 2-7Database Compatibility Issues for Sybase.......................................................................................... 2-7

Chained Mode .................................................................................................................................... 2-7Column Definitions............................................................................................................................ 2-7Naming Rules ..................................................................................................................................... 2-7

Rules for Naming Objects .......................................................................................................... 2-7Case Sensitivity ........................................................................................................................... 2-8

Data Types........................................................................................................................................... 2-8Binary Literal Notation .............................................................................................................. 2-8Data Type Conversion................................................................................................................ 2-9

Queries................................................................................................................................................. 2-9Row Selection .............................................................................................................................. 2-9Empty Strings .............................................................................................................................. 2-9

iv

Empty Bind Variables.............................................................................................................. 2-10Locking ............................................................................................................................................. 2-10Sybase Identifiers Length Limit .................................................................................................... 2-10

Known Restrictions .............................................................................................................................. 2-10Transactional Integrity .................................................................................................................. 2-11Transaction Capability .................................................................................................................. 2-11COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open Cursors .......................... 2-11Stored Procedures ........................................................................................................................... 2-11Pass-Through Feature..................................................................................................................... 2-12Sybase NCHAR and NVARCHAR Data Types ......................................................................... 2-12SQL Syntax ....................................................................................................................................... 2-12

WHERE CURRENT OF Clause.............................................................................................. 2-12CONNECT BY Clause ............................................................................................................. 2-12ROWID ...................................................................................................................................... 2-12Subqueries in INSERT Statement .......................................................................................... 2-12EXPLAIN PLAN Statement.................................................................................................... 2-13Callback Support...................................................................................................................... 2-13

SQL*Plus COPY Command with Lowercase Table Names...................................................... 2-13Database Links................................................................................................................................. 2-13CALLBACK links ............................................................................................................................ 2-13

Known Problems ................................................................................................................................... 2-14Encrypted Format Login ............................................................................................................... 2-14Date Arithmetic ............................................................................................................................... 2-14Sybase IMAGE and TEXT Data Type........................................................................................... 2-14String Functions............................................................................................................................... 2-15Schema Names and PL/SQL......................................................................................................... 2-15Data Dictionary Views and PL/SQL............................................................................................ 2-15Stored Procedures ........................................................................................................................... 2-15

3 Case Studies

Case Descriptions ..................................................................................................................................... 3-1Distribution Media Contents................................................................................................................. 3-2Demonstration Files................................................................................................................................. 3-2Demonstration Requirements................................................................................................................ 3-2Creating Demonstration Tables ............................................................................................................ 3-2

Demonstration Table Definitions..................................................................................................... 3-3Demonstration Table Contents ........................................................................................................ 3-4

Case 1: Simple Queries ........................................................................................................................... 3-5Case 2: A More Complex Query ............................................................................................................ 3-5Case 3: Joining Sybase Tables ............................................................................................................... 3-5Case 4: Write Capabilities....................................................................................................................... 3-5

DELETE Statement............................................................................................................................. 3-5UPDATE Statement ........................................................................................................................... 3-5INSERT Statement.............................................................................................................................. 3-5

Case 5: Data Dictionary Query .............................................................................................................. 3-6Case 6: The Pass-Through Feature ........................................................................................................ 3-6

UPDATE Statement ........................................................................................................................... 3-6

v

SELECT Statement ............................................................................................................................. 3-6Case 7: Executing Stored Procedures .................................................................................................... 3-6

A Data Type Conversion

Data Type Conversion............................................................................................................................ A-1

B Supported SQL Syntax and Functions

Supported SQL Statements ................................................................................................................... B-1DELETE .............................................................................................................................................. B-1INSERT ............................................................................................................................................... B-1SELECT............................................................................................................................................... B-1UPDATE ............................................................................................................................................. B-2

Oracle Functions ...................................................................................................................................... B-2Functions Not Supported by Sybase .............................................................................................. B-2Functions Supported by Sybase ...................................................................................................... B-2

Arithmetic Operators................................................................................................................. B-2Comparison Operators.............................................................................................................. B-3Group Functions ........................................................................................................................ B-3String Functions ......................................................................................................................... B-3Other Functions.......................................................................................................................... B-3

C Data Dictionary

Data Dictionary Support........................................................................................................................ C-1Sybase System Tables ....................................................................................................................... C-1Accessing the Gateway Data Dictionary ....................................................................................... C-1Direct Queries to Sybase Tables ...................................................................................................... C-2Supported Views and Tables........................................................................................................... C-2

Data Dictionary Mapping...................................................................................................................... C-3Default Column Values .................................................................................................................... C-4

Gateway Data Dictionary Descriptions .............................................................................................. C-4

D Initialization Parameters

Initialization Parameter File Syntax .................................................................................................... D-1Oracle Database Gateway for Sybase Initialization Parameters ................................................... D-2Initialization Parameter Description ................................................................................................... D-3

HS_CALL_NAME ............................................................................................................................ D-3HS_DB_DOMAIN ............................................................................................................................ D-4HS_DB_INTERNAL_NAME .......................................................................................................... D-4HS_DB_NAME ................................................................................................................................. D-4HS_DESCRIBE_CACHE_HWM .................................................................................................... D-5HS_LANGUAGE ............................................................................................................................. D-5

Character Sets ............................................................................................................................. D-5Language..................................................................................................................................... D-6Territory....................................................................................................................................... D-6

HS_LONG_PIECE_TRANSFER_SIZE ......................................................................................... D-6

vi

HS_OPEN_CURSORS .................................................................................................................... D-6HS_RPC_FETCH_REBLOCKING ................................................................................................ D-7HS_RPC_FETCH_SIZE ................................................................................................................... D-7HS_TIME_ZONE .............................................................................................................................. D-7HS_TRANSACTION_MODEL ....................................................................................................... D-8IFILE ................................................................................................................................................... D-8HS_FDS_TIMESTAMP_MAPPING................................................................................................ D-9HS_FDS_DATE_MAPPING ............................................................................................................ D-9HS_FDS_CONNECT_INFO ............................................................................................................ D-9HS_FDS_PROC_IS_FUNC............................................................................................................. D-10HS_FDS_RECOVERY_ACCOUNT .............................................................................................. D-10HS_FDS_RECOVERY_PWD.......................................................................................................... D-10HS_FDS_RESULTSET_SUPPORT ................................................................................................ D-10HS_FDS_TRACE_LEVEL............................................................................................................... D-11HS_FDS_TRANSACTION_LOG .................................................................................................. D-11HS_FDS_FETCH_ROWS................................................................................................................ D-11HS_FDS_QUOTE_IDENTIFIER.................................................................................................... D-12HS_IDLE_TIMEOUT ...................................................................................................................... D-12HS_NLS_LENGTH_SEMANTICS................................................................................................ D-12HS_KEEP_REMOTE_COLUMN_SIZE........................................................................................ D-12HS_FDS_REMOTE_DB_CHARSET ............................................................................................. D-13HS_FDS_SUPPORT_STATISTICS ................................................................................................ D-13HS_FDS_RSET_RETURN_ROWCOUNT.................................................................................... D-13HS_FDS_SQLLEN_INTERPRETATION ..................................................................................... D-14HS_FDS_REPORT_REAL_AS_DOUBLE .................................................................................... D-14HS_FDS_ARRAY_EXEC ................................................................................................................ D-14

Index

viii

List of Tables

A–1 Data Type Mapping and Restrictions ................................................................................... A-1C–1 Oracle Data Dictionary View Names and Sybase Equivalents .......................................... C-3C–2 ALL_CATALOG ....................................................................................................................... C-4C–3 ALL_COL_COMMENTS ......................................................................................................... C-4C–4 ALL_CONS_COLUMNS ......................................................................................................... C-4C–5 ALL_CONSTRAINTS............................................................................................................... C-5C–6 ALL_IND_COLUMNS............................................................................................................. C-5C–7 ALL_INDEXES .......................................................................................................................... C-6C–8 ALL_OBJECTS........................................................................................................................... C-7C–9 ALL_TAB_COLUMNS............................................................................................................. C-7C–10 ALL_TAB_COMMENTS.......................................................................................................... C-8C–11 ALL_TABLES............................................................................................................................. C-8C–12 ALL_USERS ............................................................................................................................. C-10C–13 ALL_VIEWS............................................................................................................................. C-10C–14 DBA_CATALOG..................................................................................................................... C-10C–15 DBA_COL_COMMENTS....................................................................................................... C-10C–16 DBA_OBJECTS ........................................................................................................................ C-11C–17 DBA_TAB_COLUMNS .......................................................................................................... C-11C–18 DBA_TAB_COMMENTS....................................................................................................... C-12C–19 DBA_TABLES.......................................................................................................................... C-12C–20 DICT_COLUMNS ................................................................................................................... C-13C–21 DICTIONARY.......................................................................................................................... C-13C–22 DUAL........................................................................................................................................ C-14C–23 TABLE_PRIVILEGES ............................................................................................................. C-14C–24 USER_CATALOG ................................................................................................................... C-14C–25 USER_COL_COMMENTS..................................................................................................... C-14C–26 USER_CONS_COLUMNS ..................................................................................................... C-14C–27 USER_CONSTRAINTS .......................................................................................................... C-15C–28 USER_IND_COLUMNS......................................................................................................... C-15C–29 USER_INDEXES...................................................................................................................... C-15C–30 USER_OBJECTS ...................................................................................................................... C-17C–31 USER_TAB_COLUMNS ........................................................................................................ C-17C–32 USER_TAB_COMMENTS ..................................................................................................... C-18C–33 USER_TABLES ........................................................................................................................ C-18C–34 USER_USERS........................................................................................................................... C-19C–35 USER_VIEWS .......................................................................................................................... C-20

ix

Preface

This manual describes the Oracle Database Gateway for Sybase, which enables Oracleclient applications to access Sybase data through Structured Query Language (SQL).The gateway, with the Oracle database, creates the appearance that all data resides ona local Oracle database, even though the data can be widely distributed.

This preface covers the following topics:

■ Audience

■ Documentation Accessibility

■ Related Documents

■ Conventions

AudienceThis manual is intended for Oracle database administrators who perform thefollowing tasks:

■ Installing and configuring the Oracle Database Gateway for Sybase

■ Diagnosing gateway errors

■ Using the gateway to access Sybase data

Documentation AccessibilityFor information about Oracle's commitment to accessibility, visit the OracleAccessibility Program website athttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=docacc.

Access to Oracle SupportOracle customers that have purchased support have access to electronic supportthrough My Oracle Support. For information, visithttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=info or visithttp://www.oracle.com/pls/topic/lookup?ctx=acc&id=trs if you are hearingimpaired.

Note: You should understand the fundamentals of OracleDatabase Gateways and the UNIX based platform before using thisguide to install or administer the gateway.

x

Related DocumentsFor more information, see the following documents:

■ Oracle Database New Features Guide

■ Oracle Call Interface Programmer's Guide

■ Oracle Database Administrator's Guide

■ Oracle Database Development Guide

■ Oracle Database Concepts

■ Oracle Database Performance Tuning Guide

■ Oracle Database Error Messages

■ Oracle Database Globalization Support Guide

■ Oracle Database Reference

■ Oracle Database SQL Language Reference

■ Oracle Database Net Services Administrator's Guide

■ SQL*Plus User's Guide and Reference

■ Oracle Database Heterogeneous Connectivity User's Guide

■ Oracle Database Security Guide

Many of the examples in this book use the sample schemas of the seed database, whichis installed by default when you install Oracle. Refer to Oracle Database Sample Schemasfor information on how these schemas were created and how you can use themyourself.

ConventionsThe following text conventions are used in this document:

Convention Meaning

boldface Boldface type indicates graphical user interface elements associatedwith an action, or terms defined in text or the glossary.

italic Italic type indicates book titles, emphasis, or placeholder variables forwhich you supply particular values.

monospace Monospace type indicates commands within a paragraph, URLs, codein examples, text that appears on the screen, or text that you enter.

1

Introduction 1-1

1 Introduction

This chapter introduces the challenge faced by organizations when running severaldifferent database systems. It briefly covers Heterogeneous Services, the technologythat the Oracle Database Gateway for Sybase is based on.

To get a good understanding of generic gateway technology, Heterogeneous Services,and how Oracle Database Gateways fit in the picture, reading the Oracle DatabaseHeterogeneous Connectivity User's Guide first is highly recommended.

This chapter contains the following sections:

■ Overview

■ Heterogeneous Services Technology

■ Oracle Database Gateways

OverviewHeterogeneous data access is a problem that affects a lot of companies. A lot ofcompanies run several different database systems. Each of these systems stores dataand has a set of applications that run against it. Consolidation of this data in onedatabase system is often hard - in large part because that many of the applications thatrun against one database may not have an equivalent that runs against another. Untilsuch time as migration to one consolidated database system is made feasible, it isnecessary for the various heterogeneous database systems to interoperate.

Oracle Database Gateways provide the ability to transparently access data residing ina non-Oracle system from an Oracle environment. This transparency eliminates theneed for application developers to customize their applications to access data fromdifferent non-Oracle systems, thus decreasing development efforts and increasing themobility of the application. Applications can be developed using a consistent Oracleinterface for both Oracle and Sybase.

Gateway technology is composed of two parts: a component that has the generictechnology to connect to a non-Oracle system, which is common to all the non-Oraclesystems, called Heterogeneous Services, and a component that is specific to thenon-Oracle system that the gateway connects to. Heterogeneous Services, inconjunction with the Oracle Database Gateway agent, enables transparent access tonon-Oracle systems from an Oracle environment.

Heterogeneous Services TechnologyHeterogeneous Services provides the generic technology for connecting to non-Oraclesystems. As an integrated component of the database, Heterogeneous Services can

Oracle Database Gateways

1-2 Oracle Database Gateway for Sybase User's Guide

exploit features of the database, such as the powerful SQL parsing and distributedoptimization capabilities.

Heterogeneous Services extend the Oracle SQL engine to recognize the SQL andprocedural capabilities of the remote non-Oracle system and the mappings required toobtain necessary data dictionary information. Heterogeneous Services provides twotypes of translations: the ability to translate Oracle SQL into the proper dialect of thenon-Oracle system as well as data dictionary translations that displays the metadata ofthe non-Oracle system in the local format. For situations where no translations areavailable, native SQL can be issued to the non-Oracle system using the pass-throughfeature of Heterogeneous Services.

Heterogeneous Services also maintains the transaction coordination between Oracleand the remote non-Oracle system, such as providing the two-phase commit protocolto ensure distributed transaction integrity, even for non-Oracle systems that do notnatively support two-phase commit.

Oracle Database GatewaysThe capabilities, SQL mappings, data type conversions, and interface to the remotenon-Oracle system are contained in the gateway. The gateway interacts withHeterogeneous Services to provide the transparent connectivity between Oracle andnon-Oracle systems.

The gateway can be installed on any machine independent of the Oracle or non-Oracledatabase. It can be the same machine as the Oracle database or on the same machine asthe Sybase database or on a third machine as a standalone. Each configuration has itsadvantages and disadvantages. The issues to consider when determining where toinstall the gateway are network traffic, operating system platform availability,hardware resources and storage.

See Also: Oracle Database Heterogeneous Connectivity User's Guidefor more information about Heterogeneous Services.

2

Sybase Gateway Features and Restrictions 2-1

2 Sybase Gateway Features and Restrictions

After the gateway is installed and configured, you can use the gateway to accessSybase data, pass Sybase commands from applications to the Sybase database,perform distributed queries, and copy data.


■ Using the Pass-Through Feature

■ Executing Stored Procedures and Functions

■ CHAR Semantics

■ Multi-byte Character Sets Ratio Suppression

■ IPv6 Support

■ Gateway Session IDLE Timeout

■ Database Compatibility Issues for Sybase

■ Known Restrictions

■ Known Problems

Using the Pass-Through FeatureThe gateway can pass Sybase commands or statements from the application to theSybase database using the DBMS_HS_PASSTHROUGH package.

Use the DBMS_HS_PASSTHROUGH package in a PL/SQL block to specify the statement tobe passed to the Sybase database, as follows:

DECLAREnum_rows INTEGER;

BEGINnum_rows := DBMS_HS_PASSTHROUGH.EXECUTE_IMMEDIATE@SYBS('command');

END;/

Where command cannot be one of the following:

■ BEGIN TRANSACTION

■ COMMIT

■ ROLLBACK

■ SAVE

■ SHUTDOWN

Executing Stored Procedures and Functions


■ Sybase tool commands

The DBMS_HS_PASSTHROUGH package supports passing bind values and executingSELECT statements.

Executing Stored Procedures and FunctionsUsing the procedural feature, the gateway can execute stored procedures that aredefined in the Sybase database. It is not necessary to relink the gateway or define theprocedure to the gateway, but the procedure's access privileges must permit access bythe gateway.

Standard PL/SQL statements are used to execute a stored procedure.

The gateway supports stored procedures in three mutually exclusive modes:

■ Normal mode: Have access to IN/OUT arguments only

■ Return value mode: Have a return value for all stored procedures

■ Resultset mode: Out values are available as last result set

Return Values and Stored ProceduresBy default, all stored procedures and functions do not return a return value to the user.To enable return values, set the HS_FDS_PROC_IS_FUNC parameter in the initializationparameter file.

In the following example, the employee name JOHN SMYTHE is passed to the Sybasestored procedure REVISE_SALARY. The stored procedure retrieves the salary value fromthe Sybase database to calculate a new yearly salary for JOHN SMYTHE. The revisedsalary returned in RESULT is used to update EMP in a table of an Oracle database:

DECLAREINPUT VARCHAR2(15);RESULT NUMBER(8,2);

BEGININPUT := 'JOHN SMYTHE';

Note: TRUNCATE cannot be used in a pass-through statement.

See Also: Oracle Database PL/SQL Packages and Types Reference andChapter 3, Features of Oracle Database Gateways, of OracleDatabase Heterogeneous Connectivity User's Guide for moreinformation about the DBMS_HS_PASSTHROUGH package.

See Also: Oracle Database Heterogeneous Connectivity User's Guidefor more information about executing stored procedures.

See Also: Appendix D, "Initialization Parameters" for informationabout both editing the initialization parameter file and the HS_FDS_PROC_IS_FUNC parameter.

Note: If you set the HS_FDS_PROC_IS_FUNC gateway initializationparameter, you must change the syntax of the procedure executestatement for all existing stored procedures.



RESULT := REVISE_SALARY@SYBS(INPUT);UPDATE EMP SET SAL = RESULT WHERE ENAME =: INPUT;

END;/

The procedural feature automatically converts non-Oracle data types to and fromPL/SQL data types.

Result Sets and Stored ProceduresThe Oracle Database Gateway for Sybase provides support for stored procedureswhich return result sets.

By default, all stored procedures and functions do not return a result set to the user. Toenable result sets, set the HS_FDS_RESULTSET_SUPPORT parameter in the initializationparameter file.

When accessing stored procedures with result sets through the Oracle DatabaseGateway for Sybase, you will be in the sequential mode of Heterogeneous Services.

The Oracle Database Gateway for Sybase returns the following information toHeterogeneous Services during procedure description:

■ All the input arguments of the remote stored procedure

■ None of the output arguments

■ One out argument of type ref cursor (corresponding to the first result set returnedby the stored procedure)

Client programs have to use the virtual package function dbms_hs_result_set.get_next_result_set to get the ref cursor for subsequent result sets. The last result setreturned is the out argument from the procedure.

The limitations of accessing result sets are the following:

■ Result sets returned by a remote stored procedure have to be retrieved in the orderin which they were placed on the wire

■ On execution of a stored procedure, all result sets returned by a previouslyexecuted stored procedure will be closed (regardless of whether the data has beencompletely

In the following example, the Sybase stored procedure is executed to fetch the contentsof the emp and dept tables from Sybase:

create procedure REFCURPROC (@arg1 varchar(255), @arg2 varchar(255) output)asselect @arg2 = @arg1

See Also: Appendix D, "Initialization Parameters" for informationabout both editing the initialization parameter file and the HS_FDS_RESULTSET_SUPPORT parameter. For further information aboutOracle support for result sets in non-Oracle databases see OracleDatabase Heterogeneous Connectivity User's Guide.

Note: If you set the HS_FDS_RESULTSET_SUPPORT gatewayinitialization parameter, you must change the syntax of theprocedure execute statement for all existing stored procedures orerrors will occur.



select * from EMPselect * from DEPTgo

This stored procedure assigns the input parameter arg1 to the output parameter arg2,opens the query SELECT * FROM EMP in ref cursor rc1, and opens the query SELECT *FROM DEPT in ref cursor rc2.

OCI Program Fetching from Result Sets in Sequential ModeThe following example shows OCI program fetching from result sets in sequentialmode:

OCIEnv *ENVH;OCISvcCtx *SVCH;OCIStmt *STMH;OCIError *ERRH;OCIBind *BNDH[3];OraText arg1[20];OraText arg2[255];OCIResult *rset;OCIStmt *rstmt;ub2 rcode[3];ub2 rlens[3];sb2 inds[3];OraText *stmt = (OraText *) "begin refcurproc@SYBS(:1,:2,:3); end;";OraText *n_rs_stm = (OraText *)

"begin :ret := DBMS_HS_RESULT_SET.GET_NEXT_RESULT_SET@SYBS; end;";

/* Prepare procedure call statement */

/* Handle Initialization code skipped */OCIStmtPrepare(STMH, ERRH, stmt, strlen(stmt), OCI_NTV_SYNTAX, OCI_DEFAULT);

/* Bind procedure arguments */inds[0] = 0;strcpy((char *) arg1, "Hello World");rlens[0] = strlen(arg1);OCIBindByPos(STMH, &BNDH[0], ERRH, 1, (dvoid *) arg1, 20, SQLT_CHR,

(dvoid *) &(inds[0]), &(rlens[0]), &(rcode[0]), 0, (ub4 *) 0,OCI_DEFAULT);

inds[1] = -1;OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) arg2, 20, SQLT_CHR,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]), 0, (ub4 *) 0,OCI_DEFAULT);

inds[2] = 0;rlens[2] = 0;OCIDescriptorAlloc(ENVH, (dvoid **) &rset, OCI_DTYPE_RSET, 0, (dvoid **) 0);OCIBindByPos(STMH, &BNDH[2], ERRH, 2, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[2]), &(rlens[2]), &(rcode[2]),0, (ub4 *) 0, OCI_DEFAULT);

/* Execute procedure */OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

Note: Chained mode must be set before creating the storedprocedure. Issue the following command in Sybase: set chainedon



(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert result set to statement handle */OCIResultSetToStmt(rset, ERRH);rstmt = (OCIStmt *) rset;

/* After this the user can fetch from rstmt *//* Issue get_next_result_set call to get handle to next_result set *//* Prepare Get next result set procedure call */

OCIStmtPrepare(STMH, ERRH, n_rs_stm, strlen(n_rs_stm), OCI_NTV_SYNTAX,OCI_DEFAULT);

/* Bind return value */OCIBindByPos(STMH, &BNDH[1], ERRH, 1, (dvoid *) rset, 0, SQLT_RSET,

(dvoid *) &(inds[1]), &(rlens[1]), &(rcode[1]),0, (ub4 *) 0, OCI_DEFAULT);

/* Execute statement to get next result set*/OCIStmtExecute(SVCH, STMH, ERRH, 1, 0, (CONST OCISnapshot *) 0,

(OCISnapshot *) 0, OCI_DEFAULT);

/* Convert next result set to statement handle */OCIResultSetToStmt(rset, ERRH);rstmt = (OCIStmt *) rset;

/* Now rstmt will point to the second result set returned by theremote stored procedure */

/* Repeat execution of get_next_result_set to get the output arguments */

PL/SQL Program Fetching from Result Sets in Sequential ModeAssume that the table loc_emp is a local table exactly like the Sybase emp table. Thesame assumption applies for loc_dept. outargs is a table with columns correspondingto the out arguments of the Sybase stored procedure.

create or replace package rcpackage istype RCTYPE is ref cursor;

end rcpackage;/declare

rc1 rcpackage.rctype;rec1 loc_emp%rowtype;rc2 rcpackage.rctype;rec2 loc_dept%rowtype;rc3 rcpackage.rctype;rec3 outargs%rowtype;out_arg varchar2(255);

begin

-- Execute procedureout_arg := null;refcurproc@SYBS('Hello World', out_arg, rc1);

-- Fetch 20 rows from the remote emp table and insert them into loc_empfor i in 1 .. 20 loop

fetch rc1 into rec1;insert into loc_emp (rec1.empno, rec1.ename, rec1.job,

CHAR Semantics


rec1.mgr, rec1.hiredate, rec1.sal, rec1.comm, rec1.deptno);end loop;

-- Close ref cursorclose rc1;

-- Get the next result set returned by the stored procedurerc2 := dbms_hs_result_set.get_next_result_set@SYBS;

-- Fetch 5 rows from the remote dept table and insert them into loc_deptfor i in 1 .. 5 loop

fetch rc2 into rec2;insert into loc_dept values (rec2.deptno, rec2.dname, rec2.loc);

end loop;

--Close ref cursorclose rc2;

-- Get the output arguments from the remote stored procedure-- Since we are in sequential mode, they will be returned in the-- form of a result setrc3 := dbms_hs_result_set.get_next_result_set@SYBS;

-- Fetch them and insert them into the outarguments tablefetch rc3 into rec3;insert into outargs (rec3.outarg, rec3.retval);

-- Close ref cursorclose rc3;

end;/

CHAR SemanticsThis feature allows the gateway to optionally run in CHAR Semantics mode. Ratherthan always describing Sybase CHAR columns as CHAR(n BYTE), this feature describesthem as CHAR(n CHAR) and VARCHAR(n CHAR). The concept is similar to Oracle databaseCHAR Semantics. You need to specify HS_NLS_LENGTH_SEMANTICS=CHAR gatewayparameter to activate this option. Refer to Appendix D for more detail.

Multi-byte Character Sets Ratio SuppressionThis feature optionally suppresses the ratio expansion from Sybase database to Oracledatabase involving multi-byte character set. By default, Oracle gateways assume theworst ratio to prevent data being truncated or insufficient buffer size situation.However, if you have specific knowledge of your Sybase database and do not want theexpansion to occur, you can specify HS_KEEP_REMOTE_COLUMN_SIZE parameter tosuppress the expansion. Refer to Appendix D for more detail.

IPv6 SupportBesides full IPv6 support between Oracle databases and the gateway, IPv6 is alsosupported between this gateway and Sybase database. Refer to the HS_FDS_CONNECT_INFO parameter in Appendix D for more detail.

Database Compatibility Issues for Sybase


Gateway Session IDLE TimeoutYou can optionally choose to terminate long idle gateway sessions automatically withthe gateway parameter HS_IDLE_TIMEOUT. Specifically, when a gateway session is idlefor more than the specified time limit, the gateway session is terminated with anypending update rolled back.

Database Compatibility Issues for SybaseSybase and Oracle databases function differently in some areas, causing compatibilityproblems. The following compatibility issues are described in this section:

■ Chained Mode

■ Column Definitions

■ Naming Rules

■ Data Types

■ Queries

■ Locking

■ Sybase Identifiers Length Limit

Chained ModeThe gateway supports the ANSI-standard chained mode. Sybase stored proceduresmust be written for this mode. Running in chained mode allows the gateway to extendthe Oracle two-phase commit protection to transactions updating Oracle and Sybasedatabases.

Column DefinitionsBy default, a Sybase table column cannot contain null values unless NULL is specified inthe column definition. In compliance with the ANSI standard, the Sybase databaseoption "allow nulls by default" can be set to true to change the default columndefinition to NULL.

For an Oracle table, null values are allowed in a column unless NOT NULL is specified inthe column definition.

Naming RulesNaming rule issues include the following:

■ Rules for Naming Objects

■ Case Sensitivity

Rules for Naming ObjectsOracle and Sybase use different database object naming rules. For example, themaximum number of characters allowed for each object name can be different. Also,the use of single and double quotation marks, case sensitivity, and the use ofalphanumeric characters can all be different.

See Also: Oracle Database Reference and Sybase documentation.



Case SensitivityThe Oracle database defaults to uppercase unless you surround identifiers withdouble quote characters. For example, to refer to the Sybase table called emp, enter thename with double quote characters, as follows:

SQL> SELECT * FROM "emp"@SYBS;

However, to refer to the Sybase table called emp owned by SCOTT from an Oracleapplication, enter the following:

SQL> SELECT * FROM "Scott"."emp"@SYBS;

If the Sybase table called emp is owned by SCOTT, a table owner name in uppercaseletters, you can enter the owner name without double quote characters, as follows:

SQL> SELECT * FROM SCOTT."emp"@SYBS;

Or

SQL> SELECT * FROM scott."emp"@SYBS;

Oracle recommends that you surround all Sybase object names with double quotecharacters and use the exact letter case for the object names as they appear in theSybase data dictionary. This convention is not required when referring to thesupported Oracle data dictionary tables or views listed in Appendix C, "DataDictionary".

If existing applications cannot be changed according to these conventions, create viewsin Oracle to associate Sybase names to the correct letter case. For example, to refer tothe Sybase table emp from an existing Oracle application by using only uppercasenames, define the following view:

SQL> CREATE VIEW EMP (EMPNO, ENAME, SAL, HIREDATE)AS SELECT "empno", "ename", "sal", "hiredate"FROM "emp"@SYBS;

With this view, the application can issue statements such as the following:

SQL> SELECT EMPNO, ENAME FROM EMP;

Using views is a workaround solution that duplicates data dictionary informationoriginating in the Sybase data dictionary. You must be prepared to update the Oracleview definitions whenever the data definitions for the corresponding tables arechanged in the Sybase database.

Data TypesData type issues include the following:

■ Binary Literal Notation

■ Data Type Conversion

Binary Literal NotationOracle SQL uses hexadecimal digits surrounded by single quotes to express literalvalues being compared or inserted into columns defined as data type RAW.

This notation is not converted to syntax compatible with the Sybase VARBINARY andBINARY data types (a 0x followed by hexadecimal digits, surrounded by single quotes).

For example, the following statement is not supported:



SQL> INSERT INTO BINARY_TAB@SYBS VALUES ('0xff')

Where BINARY_TAB contains a column of data type VARBINARY or BINARY. Use bindvariables when inserting into or updating VARBINARY and BINARY data types.

Data Type ConversionSybase does not support implicit date conversions. Such conversions must be explicit.

For example, the gateway issues an error for the following SELECT statement:

SELECT DATE_COL FROM TEST@SYBSWHERE DATE_COL = "1-JAN-2001";

To avoid problems with implicit conversions, add explicit conversions, as in thefollowing:

SELECT DATE_COL FROM TEST@SYBSWHERE DATE_COL = TO_DATE("1-JAN-2001")

QueriesQuery issues include the following:

■ Row Selection

■ Empty Strings

■ Empty Bind Variables

Row SelectionSybase evaluates a query condition for all selected rows before returning any of therows. If there is an error in the evaluation process for one or more rows, no rows arereturned even though the remaining rows satisfy the condition.

Oracle evaluates the query condition row-by-row and returns a row when theevaluation is successful. Rows are returned until a row fails the evaluation.

Empty StringsOracle processes an empty string in a SQL statement as a null value. Sybase processesan empty string as an empty string.

When comparing an empty string, the gateway passes literal empty strings to theSybase database without any conversion. If you intended an empty string to representa null value, Sybase does not process the statement that way; it uses the empty string.

You can avoid this problem by using NULL or IS NULL in the SQL statement instead ofthe empty string syntax, as in the following example:

SELECT * from "emp"@SYBS where "ename" IS NULL;Selecting an empty string

For VARCHAR columns, the gateway returns an empty string to the Oracle database asNULL value.

See Also: Appendix A, "Data Type Conversion" for moreinformation about restrictions on data types.

Known Restrictions


For CHAR columns, the gateway returns the full size of the column with each characteras empty space (’ ’).

Empty Bind VariablesFor VARCHAR bind variables, the gateway passes empty bind variables to the Sybasedatabase as a NULL value.

LockingThe locking model for a Sybase database differs significantly from the Oracle model.The gateway depends on the underlying Sybase behavior, so Oracle applications thataccess Sybase through the gateway can be affected by the following possible scenarios:

■ Read access might block write access

■ Write access might block read access

■ Statement-level read consistency is not guaranteed

Sybase Identifiers Length LimitBy default, the gateway will always quote identifiers. However, certain Sybase releaseshave a limit of 30 characters for identifiers such as table or column names and quotesare considered part of the names when checking against this limit. Therefore, whenquotes are used, you can only specify 28 characters. In order to support the maximumlength limit in those Sybase releases, you need to specify HS_FDS_QUOTE_IDENTIFIER=FALSE in your gateway initialization parameter file. Setting thisinitialization parameter will cause the gateway to send identifiers without quotes.However, it has the side effect of precluding the use of identifiers that contain dots (.)or spaces, and the identifiers will follow the case sensitivity of the Sybase databasebeing used.

Known RestrictionsIf you encounter incompatibility problems not listed in this section or in "KnownProblems" on page 2-14, contact Oracle Support Services. The following sectiondescribes the known restrictions and includes suggestions for dealing with them whenpossible:

■ Transactional Integrity

■ Transaction Capability

■ COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open Cursors

■ Stored Procedures

■ Pass-Through Feature

■ Sybase NCHAR and NVARCHAR Data Types

■ SQL Syntax

■ SQL*Plus COPY Command with Lowercase Table Names

■ Database Links

■ CALLBACK links

See Also: Sybase documentation for information about theSybase locking model.

Known Restrictions


The following restriction also applies:

■ When negative numbers are used as the second parameter in a SUBSTR function,incorrect results are returned. This is due to incompatibility between the OracleSUBSTR function and the equivalent in Sybase.

Transactional IntegrityThe gateway cannot guarantee transactional integrity in the following cases:

■ When a statement that is processed by the gateway causes an implicit commit inthe target database

■ When the target database is configured to work in autocommit mode

Transaction CapabilityThe gateway does not support savepoints. If a distributed update transaction is underway involving the gateway and a user attempts to create a savepoint, the followingerror occurs:

ORA-02070: database dblink does not support savepoint in this context

By default, the gateway is configured as COMMIT_CONFIRM and it is always the commitpoint site when the Sybase database is updated by the transaction.

COMMIT or ROLLBACK in PL/SQL Cursor Loops Closes Open CursorsAny COMMIT or ROLLBACK issued in a PL/SQL cursor loop closes all open cursors,which can result in the following error:

ORA-1002: fetch out of sequence

To prevent this error, move the COMMIT or ROLLBACK statement outside the cursor loop.

Stored ProceduresChanges issued through stored procedures that embed commits or rollbacks cannot becontrolled by the Oracle transaction manager or Oracle COMMIT or ROLLBACKcommands.

When accessing stored procedures with result sets through the Oracle DatabaseGateway for Sybase, you must work in the sequential mode of HeterogeneousServices.

When accessing stored procedures with multiple result sets through the OracleDatabase Gateway for Sybase, you must read all the result sets before continuing.

Note: If you have any questions or concerns about the restrictions,contact Oracle Support Services.

Note: Oracle strongly recommends the following:

■ If you know that executing a particular statement causes animplicit commit in the target database, then ensure that thisstatement is executed in its own transaction.

■ Do not configure the target database to work in autocommitmode.

Known Restrictions


Output parameters of stored procedures must be initialized to a NULL value.

Oracle Database Gateway for Sybase does not support output parameters or storedprocedures with output parameters, inside a pass through query.

Pass-Through FeatureDDL statements executed by Sybase using the gateway pass-through feature might failif they are in a multi-statement transaction. Set the Sybase option "ddl in tran" to allowDDL statements in a transaction.

Oracle recommends that you place a DDL statement in its own transaction whenexecuting such a statement with the pass-through feature. An explicit COMMIT must beissued after the DDL statement.

If the SQL statements being passed through the gateway result in an implicit commitat the Sybase database, the Oracle transaction manager is unaware of the commit andan Oracle ROLLBACK command cannot be used to roll back the transaction.

Sybase NCHAR and NVARCHAR Data TypesThe gateway cannot select a column defined with a Sybase NCHAR or NVARCHAR datatype.

SQL SyntaxThis section lists restrictions on the following SQL syntax:

■ WHERE CURRENT OF Clause

■ CONNECT BY Clause

■ ROWID

■ Subqueries in INSERT Statement

■ EXPLAIN PLAN Statement

■ Callback Support

WHERE CURRENT OF ClauseUPDATE and DELETE statements with the WHERE CURRENT OF clause are not supported bythe gateway because they rely on the Oracle ROWID implementation. To update ordelete a specific row through the gateway, a condition style WHERE clause must be used.

CONNECT BY ClauseThe gateway does not support the CONNECT BY clause in a SELECT statement.

ROWIDThe Oracle ROWID implementation is not supported.

Subqueries in INSERT StatementSubqueries of INSERT statements cannot use multiple aliases for the same table. Forexample, the following statement is not supported:

See Also: Appendix B, "Supported SQL Syntax and Functions"for more information about restrictions on SQL syntax.

Known Restrictions


SQL> INSERT INTO "emp_target"@SYBSSELECT a."empno" FROM "emp_source"@SYBS a,

"emp_source"@SYBS b WHERE b."empno"=9999

EXPLAIN PLAN StatementThe EXPLAIN PLAN statement is not supported.

Callback SupportSQL statements that require the gateway to callback to Oracle database would not besupported.

The following categories of SQL statements will result in a callback:

■ Any DML with a sub-select, which refers to a table in Oracle database. Forexample:

INSERT INTO emp@non_oracle SELECT * FROM oracle_emp;

■ Any DELETE, INSERT, UPDATE or "SELECT... FOR UPDATE..." SQL statementcontaining SQL functions or statements that needs to be executed at theoriginating Oracle database.

These SQL functions include USER, USERENV, and SYSDATE, and the SQL statementsare in selects of data from the originating Oracle database. For example:

DELETE FROM emp@non_oracle WHERE hiredate > SYSDATE;

SELECT ename FROM tkhoemp@non_oracleWHERE hiredate IN (SELECT hiredate FROM tkhoemp)FOR UPDATE OF empno;

■ Any SQL statement that involves a table in Oracle database, and a LONG or LOBcolumn in a remote table. For example:

SELECT a.long1, b.empno FROM scott.table@non_oracle a, emp bWHERE a.id=b.empno;

SELECT a.long1, b.dummy FROM table_non@non_oracle a, dual b;

where a.long1 is a LONG column.

SQL*Plus COPY Command with Lowercase Table NamesYou need to use double quotes to wrap around lowercase table names.

For example:

copy from tkhouser/tkhouser@inst1 insert loc_tkhodept using select * from"tkhodept"@holink2;

Database LinksThe gateway is not multithreaded and cannot support shared database links. Eachgateway session spawns a separate gateway process and connections cannot beshared.

CALLBACK linksOracle Database Gateway for Sybase does not support CALLBACK links. Trying aCALLBACK link with the gateway will return the following error message:

Known Problems


ORA-02025: All tables in the SQL statement must be at the remote database

Known ProblemsThis section describes known problems and includes suggestions for correcting themwhen possible. If you have any questions or concerns about the problems, contactOracle Support Services. A current list of problems is available online. Contact yourlocal Oracle office for information about accessing the list.

The following known problems are described in this section:

■ Encrypted Format Login

■ Date Arithmetic

■ Sybase IMAGE and TEXT Data Type

■ String Functions

■ Schema Names and PL/SQL

■ Data Dictionary Views and PL/SQL

■ Stored Procedures

Encrypted Format LoginOracle database no longer supports the initialization parameter DBLINK_ENCRYPT_LOGIN. Up to version 7.3, this parameter's default TRUE value prevented the passwordfor the login user ID from being sent over the network (in the clear). Later versionsautomatically encrypt the password.

Date ArithmeticThe following SQL expressions do not function correctly with the gateway:

date + numbernumber + datedate - numberdate1 - date2

Statements with the preceding expressions are sent to the Sybase database without anytranslation. Since Sybase does not support these date arithmetic functions, thestatements return an error.

Sybase IMAGE and TEXT Data TypeThe following restrictions apply when using IMAGE and TEXT data types:

■ An unsupported SQL function cannot be used in a SQL statement that accesses acolumn defined as Sybase data type IMAGE or TEXT.

■ You cannot use SQL*Plus to select data from a column defined as Sybase data typeIMAGE or TEXT when the data is greater than 80 characters in length. Oraclerecommends using Pro*C or Oracle Call Interface to access such data in a Sybasedatabase.

■ IMAGE and TEXT data cannot be read through pass-through queries.

The gateway does not support the PL/SQL function COLUMN_VALUE_LONG of the DBMS_SQL package.

Known Problems


String FunctionsIf you concatenate numeric literals using the "||" operator when using the gateway toquery a Sybase database, the result is an arithmetic addition. For example, the result ofthe following statement is 18:

SQL> SELECT 9 || 9 FROM DUAL@SYBS;

The result is 99 when using Oracle to query an Oracle database.

Schema Names and PL/SQLIf you do not prefix a Sybase database object with its schema name in a SQL statementwithin a PL/SQL block, the following error message occurs:

ORA-6550 PLS-201 Identifier table_name must be declared.

Change the SQL statement to include the schema name of the object.

Data Dictionary Views and PL/SQLYou cannot refer to data dictionary views in SQL statements that are inside a PL/SQLblock.

Stored ProceduresReturn values of stored procedures that return result sets are incorrect.

See Also: Appendix B, "Supported SQL Syntax and Functions"for more information about restrictions on SQL syntax.

Known Problems


3

Case Studies 3-1

3 Case Studies

The following case studies for Sybase demonstrate some of the features of the OracleDatabase Gateway. You can verify that the gateway is installed and operating correctlyby using the demonstration files included on the distribution media.

The demonstration files are automatically copied to disk when the gateway isinstalled.


■ Case Descriptions

■ Distribution Media Contents

■ Demonstration Files

■ Demonstration Requirements

■ Creating Demonstration Tables

■ Case 1: Simple Queries

■ Case 2: A More Complex Query

■ Case 3: Joining Sybase Tables

■ Case 4: Write Capabilities

■ Case 5: Data Dictionary Query

■ Case 6: The Pass-Through Feature

■ Case 7: Executing Stored Procedures

Case DescriptionsThe cases illustrate:

■ A simple query (Case 1)

■ A more complex query (Case 2)

■ Joining Sybase tables (Case 3)

■ Write capabilities (Case 4)

■ A data dictionary query (Case 5)

■ The pass-through feature (Case 6)

■ Executing stored procedures (Case 7)

Distribution Media Contents


Distribution Media ContentsThe distribution media contains the following:

■ Demonstration files

■ One SQL script file that creates the demonstration tables and stored procedures inthe Sybase database

■ One SQL script file that drops the demonstration tables and stored proceduresfrom the Sybase database

Demonstration FilesAfter a successful gateway installation, use the demonstration files stored in thedirectory $ORACLE_HOME/dg4sybs/demo, where $ORACLE_HOME is the directory underwhich the gateway is installed. The directory contains the following demonstrationfiles:

Demonstration RequirementsThe case studies assume these requirements have been met:

■ The gateway demonstration tables and stored procedures are installed in theSybase database

■ The Oracle database has an account named SCOTT with a password of TIGER

■ The Oracle database has a database link called GTWLINK (set up as public or privateto the user SCOTT) that connects the gateway to a Sybase database as SCOTT withpassword TIGER2.

For example, you can create the database link as follows:

SQL> CREATE DATABASE LINK GTWLINK CONNECT TO SCOTT2 IDENTIFIED BY TIGER2 USING 'GTWSID';

■ Oracle Net Services is configured correctly and running

■ The Sybase environment variable, SYBASE, is set correctly

Creating Demonstration TablesThe case studies are based on the GTW_EMP, GTW_DEPT, and GTW_SALGRADE tables and thestored procedures InsertDept and GetDept. If the demonstration tables and storedprocedures have not been created in the Sybase database, use the bldsybs.sql scriptto create them. Enter the following:

$ isql -USCOTT -PTIGER2 -ibldsybs.sql

Demonstration Files Demonstration Files

bldsybs.sql case4c.sql

case1.sql case5.sql

case2.sql case6a.sql

case3.sql case6b.sql

case4a.sql case7.sql

case4b.sql dropsybs.sql

Creating Demonstration Tables

Case Studies 3-3

The script creates the demonstration tables and stored procedures in the Sybasedatabase accordingly:

CREATE TABLE GTW_EMP (EMPNO SMALLINT NOT NULLENAME VARCHAR(10),JOB VARCHAR(9),MGR SMALLINT,HIREDATE DATETIME,SAL NUMERIC(7,2),COMM NUMERIC(7,2),DEPTNO SMALLINT)go

CREATE TABLE GTW_DEPT (DEPTNO SMALLINT NOT NULL,DNAME VARCHAR(14),LOC VARCHAR(13))go

CREATE TABLE GTW_SALGRADE (GRADE MONEY,LOSAL NUMERIC(9,4),HISAL NUMERIC(9,4))go

SET CHAINED ONgo

DROP PROCEDURE InsertDeptgo

CREATE PROCEDURE InsertDept (@dno INTEGER,@dname VARCHAR(14), @loc VARCHAR(13))

AS INSERT INTO GTW_DEPT VALUES (@dno, @dname, @loc)go

DROP PROCEDURE GetDeptgo

CREATE PROCEDURE GetDept (@dno INTEGER, @dname VARCHAR(14) OUTPUT)AS SELECT @dname=DNAME FROM GTW_DEPT WHERE DEPTNO=@dnogo

Demonstration Table DefinitionsThe table definitions are listed in the following table using information retrieved bythe SQL*PLUS DESCRIBE command:

GTW_EMP

Name Null? Type------------------------------- -------- ----EMPNO NOT NULL NUMBER(5)ENAME VARCHAR2(10)JOB VARCHAR2(9)MGR NUMBER(5)HIREDATE DATESAL NUMBER(7,2)COMM NUMBER(7,2)

Creating Demonstration Tables


DEPTNO NUMBER(5)

GTW_DEPT

Name Null? Type------------------------------- -------- ----DEPTNO NOT NULL NUMBER(5)DNAME VARCHAR2(14)LOC VARCHAR2(13)

GTW_SALGRADE

Name Null? Type------------------------------- -------- ----GRADE NUMBER(19,4)LOSAL NUMBER(9,4)HISAL NUMBER(9,4)

Demonstration Table ContentsThe contents of the Sybase tables are:

GTW_EMP

EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO----- ----- --- --- -------- --- ---- ------7369 SMITH CLERK 7902 17-DEC-80 800 207499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 307521 WARD SALESMAN 7698 22-FEB-81 1250 500 307566 JONES MANAGER 7839 02-APR-81 2975 207654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 307698 BLAKE MANAGER 7839 01-MAY-81 2850 307782 CLARK MANAGER 7839 09-JUN-81 2450 107788 SCOTT ANALYST 7566 09-DEC-82 3000 207839 KING PRESIDENT 17-NOV-81 5000 107844 TURNER SALESMAN 7698 08-SEP-81 1500 0 307876 ADAMS CLERK 7788 12-JAN-83 1100 207900 JAMES CLERK 7698 03-DEC-81 950 307902 FORD ANALYST 7566 03-DEC-81 3000 207934 MILLER CLERK 7782 23-JAN-82 1300 10

GTW_DEPT

DEPTNO DNAME LOC----- -------------- --------

10 ACCOUNTING NEW YORK20 RESEARCH DALLAS30 SALES CHICAGO40 OPERATIONS BOSTON

GTW_SALGRADE

GRADE LOSAL HISAL------ ------ -----

1 700 12002 1201 14003 1401 20004 2001 30005 3001 9999

Case 4: Write Capabilities

Case Studies 3-5

Case 1: Simple QueriesCase 1 demonstrates the following:

■ A simple query

■ A simple query retrieving full date information

The first query retrieves all the data from GTW_DEPT and confirms that the gateway isworking correctly. The second query retrieves all the data from GTW_EMP including thetime portion of the hire date because the default date format was set to DD-MON-YYHH24:MM:SS for the session by an ALTER SESSION command.

Case 2: A More Complex QueryCase 2 demonstrates the following:

■ The functions SUM(expression) and NVL(expr1, expr2) in the SELECT list

■ The GROUP BY and HAVING clauses

This query retrieves the departments from GTW_EMP whose total monthly expenses arehigher than $10,000.

Case 3: Joining Sybase TablesCase 3 demonstrates the following:

■ Joins between Sybase tables

■ Subselects

The query retrieves information from three Sybase tables and relates the employees totheir department name and salary grade, but only for those employees earning morethan the average salary.

Case 4: Write CapabilitiesCase 4 is split into three cases and demonstrates the following:

■ DELETE Statement

■ UPDATE Statement

■ INSERT Statement

DELETE StatementCase 4a demonstrates bind values and subselect. All employees in department 20 andone employee, WARD, in department 30 are deleted.

UPDATE StatementCase 4b provides an example of a simple UPDATE statement. In this example,employees are given a $100 a month salary increase.

INSERT StatementCase 4c is an example of a simple insert statement that does not provide informationfor all columns.

Case 5: Data Dictionary Query


Case 5: Data Dictionary QueryCase 5 demonstrates data dictionary mapping. It retrieves all the tables and views thatexist in the Sybase database that begin with "GTW".

Case 6: The Pass-Through FeatureCase 6 demonstrates the gateway pass-through feature that allows an application tosend commands or statements to Sybase.

This case demonstrates:

■ A pass-through UPDATE statement using bind variables

■ A pass-through SELECT statement

UPDATE StatementCase 6a provides an example of a pass-through UPDATE statement with bind variables.In this example, the salary for EMPNO 7934 is set to 4000.

SELECT StatementCase 6b provides an example of a pass-through SELECT statement. The data that isreturned from the SELECT statement is inserted into a local table at the Oracle database.

Case 7: Executing Stored ProceduresCase 7 demonstrates the gateway executing a stored procedure in the Sybase database.

Before running the script, make sure that chained mode is set on, by issuing thefollowing command in Sybase:

set chained on

A

Data Type Conversion A-1

A Data Type Conversion

This appendix contains the following section:

■ Data Type Conversion

Data Type ConversionThe gateway converts Sybase data types to Oracle data types as follows:

Table A–1 Data Type Mapping and Restrictions

Sybase Oracle CommentIf Oracle uses large varchar(32k)

BIGINT NUMBER(19)

BINARY RAW -

BIT NUMBER(3) -

CHAR CHAR -

DATE DATE

DATETIME DATE -

DECIMAL NUMBER(p[,s]) -

FLOAT FLOAT(53) -

IMAGE LONG RAW -

INT NUMBER(10) NUMBER range is -2,147,483,647to 2,147,483,647

MONEY NUMBER(p[,s]) -

NUMERIC NUMBER(p[,s]) -

REAL FLOAT(24) -

SMALLDATETIME DATE -

SMALLINT NUMBER(5) NUMBER range is -32,767 to32,767

SMALLMONEY NUMBER(p[,s]) -

SYSNAME VARCHAR2

TEXT LONG -

TIME CHAR(15)

TIMESTAMP RAW

Data Type Conversion

A-2 Oracle Database Gateway for Sybase User's Guide

TINYINT NUMBER(3) -

UNICHAR NCHAR -

UNSIGNED BIGINT NUMBER(20)

UNSIGNED INT NUMBER(10)

UNSIGNED SMALLINT NUMBER(5)

UNITEXT LONG if Oracle DB Character Set =Unicode. Otherwise, it is notsupported

UNIVARCHAR NVARCHAR -

VARBINARY RAW -

VARCHAR VARCHAR2 N < = 4000 N <= 32767

Table A–1 (Cont.) Data Type Mapping and Restrictions

Sybase Oracle CommentIf Oracle uses large varchar(32k)

B

Supported SQL Syntax and Functions B-1

B Supported SQL Syntax and Functions

This appendix contains the following sections:

■ Supported SQL Statements

■ Oracle Functions

Supported SQL StatementsWith a few exceptions, the gateway provides full support for Oracle DELETE, INSERT,SELECT, and UPDATE statements.

The gateway does not support Oracle data definition language (DDL) statements. Noform of the Oracle ALTER, CREATE, DROP, GRANT, or TRUNCATE statements can be used.Instead, for ALTER, CREATE, DROP, and GRANT statements, use the pass-through feature ofthe gateway if you need to use DDL statements against the Sybase database.

DELETEThe DELETE statement is fully supported. However, only Oracle functions supportedby Sybase can be used.

INSERTThe INSERT statement is fully supported. However, only Oracle functions supportedby Sybase can be used.

SELECTThe SELECT statement is fully supported, with these exceptions:

Note: TRUNCATE cannot be used in a pass-through statement.

See Also: Oracle Database SQL Language Reference for detaileddescriptions of keywords, parameters, and options and the Sybasedocumentation for details of executing SQL statements in atransaction.

See Also: "Functions Supported by Sybase" on page B-2 for a listof supported functions.


Oracle Functions

B-2 Oracle Database Gateway for Sybase User's Guide

■ CONNECT BY condition

■ NOWAIT

■ START WITH condition

■ WHERE CURRENT OF

UPDATEThe UPDATE statement is fully supported. However, only Oracle functions supportedby Sybase can be used. Also, you cannot have SQL statements in the subquery thatrefer to the same table name in the outer query. Subqueries are not supported in theSET clause.

Oracle FunctionsAll functions are evaluated by the Sybase database after the gateway has convertedthem to Sybase SQL.

Functions Not Supported by SybaseOracle SQL functions with no equivalent function in Sybase are not supported inDELETE, INSERT, or UPDATE statements, but are evaluated by the Oracle database if thestatement is a SELECT statement. That is, the Oracle database performs post-processingof SELECT statements sent to the gateway.

If an unsupported function is used in a DELETE, INSERT, or UPDATE, statement, thefollowing Oracle error occurs:

ORA-02070: database db_link_name does not support function in this context

Functions Supported by SybaseThe gateway translates the following Oracle database functions in SQL statements totheir equivalent Sybase functions:

■ Arithmetic Operators

■ Comparison Operators

■ Group Functions

■ String Functions

■ Other Functions

Arithmetic Operators


Oracle Sybase

+ +

- -

* *

/ /

Oracle Functions

Supported SQL Syntax and Functions B-3

Comparison Operators

Group Functions

String Functions

Other Functions

Oracle Sybase

= =

> >

< <

>= >=

<= <=

<>, !=, ^= <>, !=

IS NOT NULL IS NOT NULL

IS NULL IS NULL

Oracle Sybase

AVG AVG

COUNT COUNT

MAX MAX

MIN MIN

SUM SUM

Oracle Sybase

|| + (expression1 + expression2)

ASCII ASCII

CHR CHAR

INSTR CHARINDEX

LENGTH CHAR_LENGTH

LOWER LOWER

SUBSTR (second argument cannot be anegative number)

SUBSTRING

UPPER UPPER

Oracle Sybase

ABS ABS

CEIL CEILING

COS COS

EXP EXP

Oracle Functions

B-4 Oracle Database Gateway for Sybase User's Guide

FLOOR FLOOR

LN LOG

LOG LOG10

MOD %

NOT NVL IS NOT NULL

NVL IS NULL

POWER POWER

ROUND ROUND

SIN SIN

SQRT SQRT

TAN TAN

Oracle Sybase

C

Data Dictionary C-1

C Data Dictionary

The Oracle Database Gateway for Sybase translates a query that refers to an Oracledatabase data dictionary table into a query that retrieves the data from Sybase systemtables. You perform queries on data dictionary tables over the database link in thesame way you query data dictionary tables in the Oracle database. The gateway datadictionary is similar to the Oracle database data dictionary in appearance and use.

This appendix contains the following sections:

■ Data Dictionary Support

■ Data Dictionary Mapping

■ Gateway Data Dictionary Descriptions

Data Dictionary SupportThe following paragraphs describe the Oracle Database Gateway for Sybase datadictionary support.

Sybase System TablesSybase data dictionary information is stored in the Sybase database as Sybase systemtables. All Sybase system tables have names prefixed with "sys". The Sybase systemtables define the structure of a database. When you change data definitions, Sybasereads and modifies the Sybase system tables to add information about the user tables.

Accessing the Gateway Data DictionaryAccessing a gateway data dictionary table or view is identical to accessing a datadictionary in an Oracle database. You issue a SQL SELECT statement specifying adatabase link. The Oracle database data dictionary view and column names are usedto access the gateway data dictionary in an Oracle database. Synonyms of supportedviews are also acceptable. For example, the following statement queries the datadictionary table ALL_CATALOG to retrieve all table names in the Sybase database:

SQL> SELECT * FROM "ALL_CATALOG"@SYBS;

When a data dictionary access query is issued, the gateway:

1. Maps the requested table, view, or synonym to one or more Sybase system tablenames. The gateway translates all data dictionary column names to theircorresponding Sybase column names within the query. If the mapping involvesone Sybase system table, the gateway translates the requested table name to its

Data Dictionary Support

C-2 Oracle Database Gateway for Sybase User's Guide

corresponding Sybase system table name within the query. If the mappinginvolves multiple Sybase system tables, the gateway constructs a join in the queryusing the translated Sybase system table names.

2. Sends the translated query to Sybase.

3. Might convert the retrieved Sybase data to give it the appearance of the Oracledatabase data dictionary table.

4. Passes the data dictionary information from the translated Sybase system table tothe Oracle database.

Direct Queries to Sybase TablesQueries issued directly to individual Sybase system tables are allowed but they returndifferent results because the Sybase system table column names differ from those ofthe data dictionary view. Also, certain columns in an Sybase system table cannot beused in data dictionary processing.

Supported Views and TablesThe gateway supports the following views and tables:

Note: The values returned when querying the gateway datadictionary might not be the same as the ones returned by the OracleSQL*Plus DESCRIBE command.

Supported Views and Tables Supported Views and Tables

ALL_CATALOG ALL_COL_COMMENTS

ALL_CONS_COLUMNS ALL_CONSTRAINTS

ALL_IND_COLUMNS ALL_INDEXES

ALL_OBJECTS ALL_TAB_COLUMNS

ALL_TAB_COMMENTS ALL_TABLES

ALL_USERS ALL_VIEWS

DBA_CATALOG DBA_COL_COMMENTS

DBA_OBJECTS DBA_TABLES

DBA_TAB_COLUMNS DBA_TAB_COMMENTS

DICT_COLUMNS DICTIONARY

DUAL TABLE_PRIVILEGES

USER_CATALOG USER_COL_COMMENTS

USER_CONS_COLUMNS USER_CONSTRAINTS

USER_IND_COLUMNS USER_INDEXES

USER_OBJECTS USER_TAB_COLUMNS

USER_TAB_COMMENTS USER_TABLES

USER_USERS USER_VIEWS

Data Dictionary Mapping

Data Dictionary C-3

No other Oracle database data dictionary tables or views are supported. If you use aview not on the list, you receive the Oracle database error code for no more rowsavailable.

Queries through the gateway of any data dictionary table or view beginning with ALL_can returns rows from the Sybase database even when access privileges for thoseSybase objects have not been granted. When querying an Oracle database with theOracle data dictionary, rows are returned only for those objects you are permitted toaccess.

Data Dictionary MappingThe tables in this section list Oracle data dictionary view names and the equivalentSybase system tables used. A plus sign (+) indicates that a join operation is involved.

Table C–1 Oracle Data Dictionary View Names and Sybase Equivalents

View Name Sybase System Table Name

ALL_CATALOG sysusers + sysobjects

ALL_COL_COMMENTS sysusers + sysobjects + syscolumns

ALL_CONS_COLUMNS sp_pkeys + sp_fkeys

ALL_CONSTRAINTS sysconstraints + sysusers + sysobjects

ALL_IND_COLUMNS sysusers + sysindexes + syscolumns

ALL_INDEXES sysusers + sysindexes + sysobjects

ALL_OBJECTS sysusers + sysobjects + sysindexes

ALL_TAB_COLUMNS sysusers + sysobjects + syscolumns

ALL_TAB_COMMENTS sysusers + sysobjects

ALL_TABLES sysusers + sysobjects

ALL_USERS sysusers

ALL_VIEWS sysusers + sysobjects + syscomments

DBA_CATALOG sysusers + sysobjects

DBA_COL_COMMENTS sysusers + sysobjects + syscolumns

DBA_OBJECTS sysusers + sysobjects + sysindexes

DBA_TABLES sysusers + sysobjects

DBA_TAB_COLUMNS sysusers + sysobjects + syscolumns

DBA_TAB_COMMENTS sysusers + sysobjects

DICT_COLUMNS sysobjects + syscolumns

DICTIONARY sysobjects

DUAL (Defined in the Gateway)

TABLE_PRIVILEGES sysprotects + sysusers + sysobjects

USER_CATALOG sysusers + sysobjects

USER_COL_COMMENTS sysusers + sysobjects + syscolumns

USER_CONS_COLUMNS sp_pkeys + sp_fkeys

USER_CONSTRAINTS sysconstraints + sysusers + sysobjects

USER_IND_COLUMNS sysusers + sysindexes + syscolumns

Gateway Data Dictionary Descriptions


Default Column ValuesThere is a minor difference between the gateway data dictionary and a typical Oracledatabase data dictionary. The Oracle database columns that are missing in an Sybasesystem table are filled with zeros, spaces, null values, not-applicable values (N.A.), ordefault values, depending on the column type.

Gateway Data Dictionary DescriptionsThe gateway data dictionary tables and views provide the following information:

■ Name, data type, and width of each column

■ The contents of columns with fixed values

They are described here with information retrieved by an Oracle SQL*Plus DESCRIBEcommand. The values in the Null? column might differ from the Oracle database datadictionary tables and views. Any default value is shown to the right of an item, butthis is not information returned by DESCRIBE.

USER_INDEXES sysusers + sysindexes + sysobjects

USER_OBJECTS sysusers + sysobjects + sysindexes

USER_TAB_COLUMNS sysusers + sysobjects + syscolumns

USER_TAB_COMMENTS sysusers + sysobjects

USER_TABLES sysusers + sysobjects

USER_USERS sysusers

USER_VIEWS sysusers + sysobjects + syscomments

Table C–2 ALL_CATALOG

Name Type Value

OWNER VARCHAR2(30) -

TABLE_NAME VARCHAR2(30) -

TABLE_TYPE VARCHAR2(5) "TABLE" or"VIEW"

Table C–3 ALL_COL_COMMENTS

Name Type Value



COLUMN_NAME VARCHAR2(30) -

COMMENTS CHAR(1) " "

Table C–4 ALL_CONS_COLUMNS

Name Type Value


Table C–1 (Cont.) Oracle Data Dictionary View Names and Sybase Equivalents

View Name Sybase System Table Name


Data Dictionary C-5

CONSTRAINT_NAME VARCHAR2(30) -



POSITION FLOAT(49) -

Table C–5 ALL_CONSTRAINTS

Name Type Value



CONSTRAINT_TYPE VARCHAR2(1) "R" or "P"


SEARCH_CONDITION VARCHAR2(1) NULL

R_OWNER VARCHAR2(30) -

R_CONSTRAINT_NAME VARCHAR2(30) -

DELETE_RULE VARCHAR2(9) "NO ACTION" or" "

STATUS VARCHAR2(7) "ENABLED"

DEFERRABLE VARCHAR2(1) NULL

DEFERRED VARCHAR2(1) NULL

VALIDATED VARCHAR2(1) NULL

GENERATED VARCHAR2(1) NULL

BAD VARCHAR2(1) NULL

RELY VARCHAR2(1) NULL

LAST_CHANGE DATE -

Table C–6 ALL_IND_COLUMNS

Name Type Value

INDEX_OWNER VARCHAR2(30) -

INDEX_NAME VARCHAR2(30) -

TABLE_OWNER VARCHAR2(30) -



COLUMN_POSITION FLOAT(49) -

COLUMN_LENGTH FLOAT(49) -

DESCEND VARCHAR(4) "DESC" or "ASC"

Table C–4 (Cont.) ALL_CONS_COLUMNS

Name Type Value



Table C–7 ALL_INDEXES

Name Type Value



INDEX_TYPE VARCHAR2(1) NULL



TABLE_TYPE VARCHAR2(7) "TABLE" or"CLUSTER"

UNIQUENESS VARCHAR2(1) NULL

COMPRESSION VARCHAR2(1) NULL

PREFIX_LENGTH NUMBER 0

TABLESPACE_NAME VARCHAR2(1) NULL

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0

INITIAL_EXTENT NUMBER 0

NEXT_EXTENT NUMBER 0

MIN_EXTENTS NUMBER 0

MAX_EXTENTS NUMBER 0

PCT_INCREASE NUMBER 0

PCT_THRESHOLD NUMBER 0

INCLUDE_COLUMN NUMBER 0

FREELISTS NUMBER 0

FREELIST_GROUPS NUMBER 0

PCT_FREE NUMBER 0

LOGGING VARCHAR2(1) NULL

BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER 0

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

CLUSTERING_FACTOR NUMBER 0

STATUS VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

SAMPLE_SIZE NUMBER 0

LAST_ANALYZED DATE NULL

DEGREE VARCHAR2(1) NULL

INSTANCES VARCHAR2(1) NULL

PARTITIONED VARCHAR2(1) NULL


Data Dictionary C-7

TEMPORARY VARCHAR2(1) NULL


SECONDARY VARCHAR2(1) NULL

BUFFER_POOL VARCHAR2(1) NULL

USER_STATS VARCHAR2(1) NULL

DURATION VARCHAR2(1) NULL

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(1) NULL

ITYP_NAME VARCHAR2(1) NULL

PARAMETERS VARCHAR2(1) NULL

GLOBAL_STATS VARCHAR2(1) NULL

DOMIDX_STATUS VARCHAR2(1) NULL

DOMIDX_OPSTATUS VARCHAR2(1) NULL

FUNCIDX_STATUS VARCHAR2(1) NULL

Table C–8 ALL_OBJECTS

Name Type Value


OBJECT_NAME VARCHAR2(30) -

SUBOBJECT_NAME VARCHAR2(1) NULL

OBJECT_ID NUMBER -

DATA_OBJECT_ID NUMBER 0

OBJECT_TYPE VARCHAR2(9) "TABLE" or"VIEW" or"PROCEDURE"

CREATED DATE -

LAST_DDL_TIME DATE -

TIMESTAMP VARCHAR2(1) NULL

STATUS VARCHAR2(5) "VALID"




Table C–9 ALL_TAB_COLUMNS

Name Type Value




Table C–7 (Cont.) ALL_INDEXES

Name Type Value



DATA_TYPE VARCHAR2(8) -

DATA_TYPE_MOD VARCHAR2(1) NULL

DATA_TYPE_OWNER VARCHAR2(1) NULL

DATA_LENGTH NUMBER -

DATA_PRECISION NUMBER -

DATA_SCALE NUMBER -

NULLABLE VARCHAR2(1) "Y" or "N"

COLUMN_ID NUMBER -

DEFAULT_LENGTH NUMBER 0

DATA_DEFAULT VARCHAR2(1) NULL

NUM_DISTINCT NUMBER 0

LOW_VALUE NUMBER 0

HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0

NUM_BUCKETS NUMBER 0



CHARACTER_SET_NAME VARCHAR2(1) NULL

CHAR_COL_DECL_LENGTH NUMBER 0



AVG_COL_LEN NUMBER 0

Table C–10 ALL_TAB_COMMENTS

Name Type Value




COMMENTS VARCHAR2(1) NULL

Table C–11 ALL_TABLES

Name Type Value



TABLESPACE_NAME CHAR(1) " "

Table C–9 (Cont.) ALL_TAB_COLUMNS

Name Type Value


Data Dictionary C-9

CLUSTER_NAME CHAR(1) " "

IOT_NAME CHAR(1) " "

PCT_FREE NUMBER(10) 0

PCT_USED NUMBER(10) 0

INI_TRANS NUMBER(10) 0

MAX_TRANS NUMBER(10) 0

INITIAL_EXTENT NUMBER(10) 0

NEXT_EXTENT NUMBER(10) 0

MIN_EXTENTS NUMBER(10) 0

MAX_EXTENTS NUMBER(10) 0

PCT_INCREASE NUMBER(10) 0

FREELISTS NUMBER(10) 0

FREELIST_GROUPS NUMBER(10) 0

LOGGING CHAR(1) " "

BACKED_UP CHAR(1) " "

NUM_ROWS NUMBER(10) 0

BLOCKS NUMBER(10) 0

EMPTY_BLOCKS NUMBER(10) 0

AVG_SPACE NUMBER(10) 0

CHAIN_CNT NUMBER(10) 0

AVG_ROW_LEN NUMBER(10) 0

AVG_SPACE_FREELIST_BLOCKS NUMBER(10) 0

NUM_FREELIST_BLOCKS NUMBER(10) 0

DEGREE CHAR(1) " "

INSTANCES CHAR(1) " "

CACHE CHAR(1) " "

TABLE_LOCK CHAR(1) " "

SAMPLE_SIZE NUMBER(10) 0


PARTITIONED CHAR(1) " "

IOT_TYPE CHAR(1) " "

TEMPORARY CHAR(1) " "

SECONDARY CHAR(1) " "

NESTED CHAR(1) " "

BUFFER_POOL CHAR(1) " "

ROW_MOVEMENT CHAR(1) " "

GLOBAL_STATS CHAR(1) " "

Table C–11 (Cont.) ALL_TABLES

Name Type Value



USER_STATS CHAR(1) " "

DURATION CHAR(1) " "

SKIP_CORRUPT CHAR(1) " "

MONITORING CHAR(1) " "

Table C–12 ALL_USERS

Name Type Value

USERNAME VARCHAR2(30) -

USER_ID NUMBER(10) -

CREATED DATE SYSDATE

Table C–13 ALL_VIEWS

Name Type Value

OWNER CHAR(30) -

VIEW_NAME CHAR(30) -

TEXT_LENGTH NUMBER(10) 0

TEXT VARCHAR2(32512) -

TYPE_TEXT_LENGTH NUMBER(10) 0

TYPE_TEXT CHAR(1) " "

OID_TEXT_LENGTH NUMBER(10) 0

OID_TEXT CHAR(1) " "

VIEW_TYPE_OWNER CHAR(1) " "

VIEW_TYPE CHAR(1) " "

Table C–14 DBA_CATALOG

Name Type Value




Table C–15 DBA_COL_COMMENTS

Name Type Value





Table C–11 (Cont.) ALL_TABLES

Name Type Value


Data Dictionary C-11

Table C–16 DBA_OBJECTS

Name Type Value




OBJECT_ID NUMBER -



CREATED DATE -







Table C–17 DBA_TAB_COLUMNS

Name Type Value









DATA_SCALE NUMBER -


COLUMN_ID NUMBER -




LOW_VALUE NUMBER 0

HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0







CHAR_COL_DEC_LENGTH NUMBER 0




Table C–18 DBA_TAB_COMMENTS

Name Type Value





Table C–19 DBA_TABLES

Name Type Value



TABLESPACE_NAME CHAR(1) " "

CLUSTER_NAME CHAR(1) " "

IOT_NAME CHAR(1) " "

PCT_FREE NUMBER(10) 0

PCT_USED NUMBER(10) 0

INI_TRANS NUMBER(10) 0

MAX_TRANS NUMBER(10) 0

INITIAL_EXTENT NUMBER(10) 0

NEXT_EXTENT NUMBER(10) 0

MIN_EXTENTS NUMBER(10) 0

MAX_EXTENTS NUMBER(10) 0

PCT_INCREASE NUMBER(10) 0

FREELISTS NUMBER(10) 0

FREELIST_GROUPS NUMBER(10) 0

LOGGING CHAR(1) " "

BACKED_UP CHAR(1) " "

NUM_ROWS NUMBER(10) 0

BLOCKS NUMBER(10) 0

Table C–17 (Cont.) DBA_TAB_COLUMNS

Name Type Value



EMPTY_BLOCKS NUMBER(10) 0

AVG_SPACE NUMBER(10) 0

CHAIN_CNT NUMBER(10) 0

AVG_ROW_LEN NUMBER(10) 0

AVG_SPACE_FREELIST_BLOCKS NUMBER(10) 0

NUM_FREELIST_BLOCKS NUMBER(10) 0

DEGREE CHAR(1) " "

INSTANCES CHAR(1) " "

CACHE CHAR(1) " "

TABLE_LOCK CHAR(1) " "

SAMPLE_SIZE NUMBER(10) 0


PARTITIONED CHAR(1) " "

IOT_TYPE CHAR(1) " "

TEMPORARY CHAR(1) " "

SECONDARY CHAR(1) " "

NESTED CHAR(1) " "

BUFFER_POOL CHAR(1) " "

ROW_MOVEMENT CHAR(1) " "

GLOBAL_STATS CHAR(1) " "

USER_STATS CHAR(1) " "

DURATION CHAR(1) " "

SKIP_CORRUPT CHAR(1) " "

MONITORING CHAR(1) " "

Table C–20 DICT_COLUMNS

Name Type Value




Table C–21 DICTIONARY

Name Type Value



Table C–19 (Cont.) DBA_TABLES

Name Type Value



Table C–22 DUAL

Name Type Value

DUMMY VARCHAR2(1) "X"

Table C–23 TABLE_PRIVILEGES

Name Type Value

GRANTEE VARCHAR2(30) -



GRANTOR VARCHAR2(30) -

SELECT_PRIV VARCHAR2(1) "Y"

INSERT_PRIV VARCHAR2(1) "A"

DELETE_PRIV VARCHAR2(1) "Y"

UPDATE_PRIV VARCHAR2(1) "A"

REFERENCES_PRIV VARCHAR2(1) "A"

ALTER_PRIV VARCHAR2(1) "Y"

INDEX_PRIV VARCHAR2(1) "Y"

CREATED DATE -

Table C–24 USER_CATALOG

Name Type Value



Table C–25 USER_COL_COMMENTS

Name Type Value




Table C–26 USER_CONS_COLUMNS

Name Type Value





POSITION NUMBER -



Table C–27 USER_CONSTRAINTS

Name Type Value



CONSTRAINT_TYPE VARCHAR2(1) "R" or "P"


SEARCH_CONDITION VARCHAR2(1) NULL

R_OWNER VARCHAR2(30) -

R_CONSTRAINT_NAME VARCHAR2(30) -

DELETE_RULE VARCHAR2(9) "NOACTION" or ""

STATUS VARCHAR2(7) "ENABLED"

DEFERRABLE VARCHAR2(1) NULL

DEFERRED VARCHAR2(1) NULL

VALIDATED VARCHAR2(1) NULL


BAD VARCHAR2(1) NULL

RELY VARCHAR2(1) NULL

LAST_CHANGE DATE -

Table C–28 USER_IND_COLUMNS

Name Type Value




COLUMN_POSITION FLOAT(49) -

COLUMN_LENGTH FLOAT(49) -

DESCEND VARCHAR(4) "DESC" or "ASC"

Table C–29 USER_INDEXES

Name Type Value


INDEX_TYPE VARCHAR2(1) NULL



TABLE_TYPE VARCHAR2(7) "TABLE" or"CLUSTER"

UNIQUENESS VARCHAR2(1) NULL

COMPRESSION VARCHAR2(1) NULL

PREFIX_LENGTH NUMBER 0




INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0






PCT_THRESHOLD NUMBER 0

INCLUDE_COLUMN NUMBER 0

FREELISTS NUMBER 0


PCT_FREE NUMBER 0


BLEVEL NUMBER 0

LEAF_BLOCKS NUMBER 0

DISTINCT_KEYS NUMBER 0

AVG_LEAF_BLOCKS_PER_KEY NUMBER 0

AVG_DATA_BLOCKS_PER_KEY NUMBER 0

CLUSTERING_FACTOR NUMBER 0


NUM_ROWS NUMBER 0











DURATION VARHCAR2(1) NULL

PCT_DIRECT_ACCESS NUMBER 0

ITYP_OWNER VARCHAR2(1) NULL

ITYP_NAME VARCHAR2(1) NULL

PARAMETERS VARCHAR2(1) NULL

Table C–29 (Cont.) USER_INDEXES

Name Type Value




DOMIDX_STATUS VARCHAR2(1) NULL

DOMIDX_OPSTATUS VARCHAR2(1) NULL

FUNCIDX_STATUS VARCHAR2(1) NULL

Table C–30 USER_OBJECTS

Name Type Value



OBJECT_ID NUMBER -



CREATED DATE -



STATUS VARCHAR2(5) "VALID"




Table C–31 USER_TAB_COLUMNS

Name Type Value








DATA_SCALE NUMBER -


COLUMN_ID NUMBER -




LOW_VALUE NUMBER 0

Table C–29 (Cont.) USER_INDEXES

Name Type Value



HIGH_VALUE NUMBER 0

DENSITY NUMBER 0

NUM_NULLS NUMBER 0





CHAR_COL_DECL_LENGTH NUMBER 0




Table C–32 USER_TAB_COMMENTS

Name Type Value




Table C–33 USER_TABLES

Name Type Value



CLUSTER_NAME VARCHAR2(1) NULL

IOT_NAME VARCHAR2(1) NULL

PCT_FREE NUMBER 0

PCT_USED NUMBER 0

INI_TRANS NUMBER 0

MAX_TRANS NUMBER 0






FREELISTS NUMBER 0



Table C–31 (Cont.) USER_TAB_COLUMNS

Name Type Value



BACKED_UP VARCHAR2(1) NULL

NUM_ROWS NUMBER 0

BLOCKS NUMBER 0

EMPTY_BLOCKS NUMBER 0

AVG_SPACE NUMBER 0

CHAIN_CNT NUMBER 0

AVG_ROW_LEN NUMBER 0

AVG_SPACE_FREELIST_BLOCKS NUMBER 0

NUM_FREELIST_BLOCKS NUMBER 0



CACHE VARCHAR2(1) NULL

TABLE_LOCK VARCHAR2(1) NULL




IOT_TYPE VARCHAR2(1) NULL

TEMPORARY VARHCAR2(1) NULL


NESTED VARCHAR2(1) NULL


ROW_MOVEMENT VARCHAR2(1) NULL



DURATION VARCHAR2(1) NULL

SKIP_CORRUPT VARCHAR2(1) NULL

MONITORING VARCHAR2(1) NULL

Table C–34 USER_USERS

Name Type Value

USERNAME VARCHAR2(30) -

USER_ID NUMBER(5) -

ACCOUNT_STATUS VARCHAR2(4) "OPEN"

LOCK_DATE DATE NULL

EXPIRY_DATE DATE NULL

DEFAULT_TABLESPACE VARCHAR2(1) NULL

TEMPORARY_TABLESPACE VARCHAR2(1) NULL

Table C–33 (Cont.) USER_TABLES

Name Type Value



CREATED DATE SYSDATE

INITIAL_RSRC_CONSUMER_GROUP VARCHAR2(1) NULL

EXTERNAL_NAME VARCHAR2(1) NULL

Table C–35 USER_VIEWS

Name Type Value

VIEW_NAME VARCHAR2(30) -

TEXT_LENGTH NUMBER 0

TEXT VARCHAR2(255) -

TYPE_TEXT_LENGTH NUMBER 0

TYPE_TEXT VARCHAR2(1) NULL

OID_TEXT_LENGTH NUMBER 0

OID_TEXT VARCHAR2(1) NULL

VIEW_TYPE_OWNER VARCHAR2(1) NULL

VIEW_TYPE VARCHAR2(1) NULL

Table C–34 (Cont.) USER_USERS

Name Type Value

D

Initialization Parameters D-1

D Initialization Parameters

The Oracle database initialization parameters in the init.ora file are distinct fromgateway initialization parameters. Set the gateway parameters in the initializationparameter file using an agent-specific mechanism, or set them in the Oracle datadictionary using the DBMS_HS package. The gateway initialization parameter file mustbe available when the gateway is started.

This appendix contains a list of the gateway initialization parameters that can be setfor each gateway and their description. It also describes the initialization parameterfile syntax. It includes the following sections:

■ Initialization Parameter File Syntax

■ Oracle Database Gateway for Sybase Initialization Parameters

■ Initialization Parameter Descriptions

Initialization Parameter File SyntaxThe syntax for the initialization parameter file is as follows:

1. The file is a sequence of commands.

2. Each command should start on a separate line.

3. End of line is considered a command terminator (unless escaped with abackslash).

4. If there is a syntax error in an initialization parameter file, none of the settings takeeffect.

5. Set the parameter values as follows:

[SET][PRIVATE] parameter=value

Where:

parameter is an initialization parameter name. It is a string of characters startingwith a letter and consisting of letters, digits and underscores. Initializationparameter names are case sensitive.

value is the initialization parameter value. It is case sensitive. An initializationparameter value is either:

a. A string of characters that does not contain any backslashes, white space ordouble quotation marks (")

b. A quoted string beginning with a double quotation mark and ending with adouble quotation mark. The following can be used inside a quoted string:

Oracle Database Gateway for Sybase Initialization Parameters

D-2 Oracle Database Gateway for Sybase User's Guide

* backslash (\) is the escape character

* \n inserts a new line

* \t inserts a tab

* \" inserts a double quotation mark

* \\ inserts a backslash

A backslash at the end of the line continues the string on the next line. If abackslash precedes any other character then the backslash is ignored.

For example, to enable tracing for an agent, set the HS_FDS_TRACE_LEVELinitialization parameter as follows:

HS_FDS_TRACE_LEVEL=ON

SET and PRIVATE are optional keywords. You cannot use either as an initializationparameter name. Most parameters are needed only as initialization parameters, soyou usually do not need to use the SET or PRIVATE keywords. If you do not specifyeither SET or PRIVATE, the parameter is used only as an initialization parameter forthe agent.

SET specifies that, in addition to being used as an initialization parameter, theparameter value is set as an environment variable for the agent process. Use SETfor parameter values that the drivers or non-Oracle system need as environmentvariables.

PRIVATE specifies that the initialization parameter should be private to the agentand should not be uploaded to the Oracle database. Most initialization parametersshould not be private. If, however, you are storing sensitive information like apassword in the initialization parameter file, then you may not want it uploadedto the server because the initialization parameters and values are not encryptedwhen uploaded. Making the initialization parameters private prevents the uploadfrom happening and they do not appear in dynamic performance views. UsePRIVATE for the initialization parameters only if the parameter value includessensitive information such as a user name or password.

SET PRIVATE specifies that the parameter value is set as an environment variablefor the agent process and is also private (not transferred to the Oracle database,not appearing in dynamic performance views or graphical user interfaces).

Oracle Database Gateway for Sybase Initialization ParametersThis section lists all the initialization file parameters that can be set for the OracleDatabase Gateway for Sybase. They are as follows:

■ HS_CALL_NAME

■ HS_DB_DOMAIN

■ HS_DB_INTERNAL_NAME

■ HS_DB_NAME

■ HS_DESCRIBE_CACHE_HWM

■ HS_LANGUAGE

■ HS_LONG_PIECE_TRANSFER_SIZE

■ HS_OPEN_CURSORS

■ HS_RPC_FETCH_REBLOCKING

Initialization Parameter Description


■ HS_RPC_FETCH_SIZE

■ HS_TIME_ZONE

■ HS_TRANSACTION_MODEL

■ IFILE

■ HS_FDS_TIMESTAMP_MAPPING

■ HS_FDS_DATE_MAPPING

■ HS_FDS_CONNECT_INFO

■ HS_FDS_PROC_IS_FUNC

■ HS_FDS_RECOVERY_ACCOUNT

■ HS_FDS_RECOVERY_PWD

■ HS_FDS_RESULTSET_SUPPORT

■ HS_FDS_TRACE_LEVEL

■ HS_FDS_TRANSACTION_LOG

■ HS_FDS_FETCH_ROWS

■ HS_FDS_QUOTE_IDENTIFIER

■ HS_IDLE_TIMEOUT

■ HS_NLS_LENGTH_SEMANTICS

■ HS_KEEP_REMOTE_COLUMN_SIZE

■ HS_FDS_REMOTE_DB_CHARSET

■ HS_FDS_SUPPORT_STATISTICS

■ HS_FDS_RSET_RETURN_ROWCOUNT

■ HS_FDS_SQLLEN_INTERPRETATION

■ HS_FDS_REPORT_REAL_AS_DOUBLE

■ HS_FDS_ARRAY_EXEC

Initialization Parameter DescriptionThe following sections describe all the initialization file parameters that can be set forgateways.

HS_CALL_NAME

Specifies the remote functions that can be referenced in SQL statements. The value is alist of remote functions and their owners, separated by semicolons, in the followingformat:

owner_name.function_name

Property Description

Default value None

Range of values Not applicable



For example:

owner1.A1;owner2.A2;owner3.A3

If an owner name is not specified for a remote function, the default owner namebecomes the user name used to connect to the remote database (specified when theHeterogeneous Services database link is created or taken from user session if notspecified in the DB link).

The entries for the owner names and the function names are case sensitive.

HS_DB_DOMAIN

Specifies a unique network sub-address for a non-Oracle system. The HS_DB_DOMAINinitialization parameter is similar to the DB_DOMAIN initialization parameter, describedin the Oracle Database Reference. The HS_DB_DOMAIN initialization parameter is requiredif you use the Oracle Names server. The HS_DB_NAME and HS_DB_DOMAIN initializationparameters define the global name of the non-Oracle system.

HS_DB_INTERNAL_NAME

Specifies a unique hexadecimal number identifying the instance to which theHeterogeneous Services agent is connected. This parameter's value is used as part of atransaction ID when global name services are activated. Specifying a nonuniquenumber can cause problems when two-phase commit recovery actions are necessaryfor a transaction.

HS_DB_NAME

Specifies a unique alphanumeric name for the data store given to the non-Oraclesystem. This name identifies the non-Oracle system within the cooperative serverenvironment. The HS_DB_NAME and HS_DB_DOMAIN initialization parameters define theglobal name of the non-Oracle system.


Default value WORLD

Range of values 1 to 199 characters

Note: The HS_DB_NAME and HS_DB_DOMAIN initialization parametersmust combine to form a unique address in a cooperative serverenvironment.


Default value 01010101

Range of values 1 to 16 hexadecimal characters


Default value HO

Range of values 1 to 8 characters



HS_DESCRIBE_CACHE_HWM

Specifies the maximum number of entries in the describe cache used byHeterogeneous Services. This limit is known as the describe cache high water mark.The cache contains descriptions of the mapped tables that Heterogeneous Servicesreuses so that it does not have to re-access the non-Oracle data store.

If you are accessing many mapped tables, increase the high water mark to improveperformance. Increasing the high water mark improves performance at the cost ofmemory usage.

HS_LANGUAGE

Provides Heterogeneous Services with character set, language, and territoryinformation of the non-Oracle data source. The value must use the following format:

language[_territory.character_set]

Character SetsIdeally, the character sets of the Oracle database and the non-Oracle data source arethe same. In almost all cases, HS_LANGUAGE should be set exactly the same as Oracledatabase character set for optimal character set mapping and performance. If they arenot the same, Heterogeneous Services attempts to translate the character set of thenon-Oracle data source to the Oracle database character set, and back again. Thetranslation can degrade performance. In some cases, Heterogeneous Services cannottranslate a character from one character set to another.

As more Oracle databases and non-Oracle databases use Unicode as databasecharacter sets, it is preferable to also run the gateway in Unicode character set. To doso, you must set HS_LANGUAGE=AL32UTF8. However, when the gateway runs onWindows, the Microsoft ODBC Driver Manager interface can exchange data only inthe double-byte character set, UCS2. This results in extra ratio expansion of describedbuffer and column sizes. Refer to HS_FDS_REMOTE_DB_CHARSET for instruction on


Default value 100

Range of values 1 to 4000


Default value System-specific

Range of values Any valid language name (up to 255 characters)

Note: The globalization support initialization parameters affecterror messages, the data for the SQL Service, and parameters indistributed external procedures.

Note: The specified character set must be a superset of theoperating system character set on the platform where the agent isinstalled.



how to adjust to correct sizes.

LanguageThe language component of the HS_LANGUAGE initialization parameter determines:

■ Day and month names of dates

■ AD, BC, PM, and AM symbols for date and time

■ Default sorting mechanism

Note that Oracle does not determine the language for error messages for the genericHeterogeneous Services messages (ORA-25000 through ORA-28000). These arecontrolled by the session settings in the Oracle database.

TerritoryThe territory clause specifies the conventions for day and week numbering, defaultdate format, decimal character and group separator, and ISO and local currencysymbols. Note that the level of globalization support between the Oracle database andthe non-Oracle data source depends on how the gateway is implemented.

HS_LONG_PIECE_TRANSFER_SIZE

Sets the size of the piece of LONG data being transferred. A smaller piece size means lessmemory requirement, but more round-trips to fetch all the data. A larger piece sizemeans fewer round-trips, but more of a memory requirement to store the intermediatepieces internally. Thus, the initialization parameter can be used to tune a system forthe best performance, with the best trade-off between round-trips and memoryrequirements, and network latency or response time.

HS_OPEN_CURSORS

Defines the maximum number of cursors that can be open on one connection to anon-Oracle system instance.

The value never exceeds the number of open cursors in the Oracle database. Therefore,setting the same value as the OPEN_CURSORS initialization parameter in the Oracledatabase is recommended.


Default value 64 KB

Range of values Any value up to 2 GB


Default value 50

Range of values 1 to the value of Oracle's OPEN_CURSORS initialization parameter



HS_RPC_FETCH_REBLOCKING

Controls whether Heterogeneous Services attempts to optimize performance of datatransfer between the Oracle database and the Heterogeneous Services agent connectedto the non-Oracle data store.

The following values are possible:

■ OFF disables reblocking of fetched data so that data is immediately sent from agentto server.

■ ON enables reblocking, which means that data fetched from the non-Oracle systemis buffered in the agent and is not sent to the Oracle database until the amount offetched data is equal or higher than the value of HS_RPC_FETCH_SIZE initializationparameter. However, any buffered data is returned immediately when a fetchindicates that no more data exists or when the non-Oracle system reports an error.

HS_RPC_FETCH_SIZE

Tunes internal data buffering to optimize the data transfer rate between the server andthe agent process.

Increasing the value can reduce the number of network round-trips needed to transfera given amount of data, but also tends to increase data bandwidth and to reducelatency as measured between issuing a query and completion of all fetches for thequery. Nevertheless, increasing the fetch size can increase latency for the initial fetchresults of a query, because the first fetch results are not transmitted until additionaldata is available.

HS_TIME_ZONE

Specifies the default local time zone displacement for the current SQL session. Theformat mask, [+|-]hh:mm, is specified to indicate the hours and minutes before orafter UTC (Coordinated Universal Time—formerly Greenwich Mean Time). Forexample:

HS_TIME_ZONE = [+ | -] hh:mm


Default value ON

Range of values OFF or ON


Default value 50000

Range of values 1 to 10000000


Default value for'[+|-]hh:mm'

Derived from the NLS_TERRITORY initialization parameter

Range of values for'[+|-]hh:mm'

Any valid datetime format mask



HS_TRANSACTION_MODEL

Specifies the type of transaction model that is used when the non-Oracle database isupdated by a transaction.

The following values are possible:

■ COMMIT_CONFIRM provides read and write access to the non-Oracle database andallows the gateway to be part of a distributed update. To use the commit-confirmmodel, the following items must be created in the non-Oracle database:

– Transaction log table. The default table name is HS_TRANSACTION_LOG. Adifferent name can be set using the HS_FDS_TRANSACTION_LOG parameter. Thetransaction log table must be granted SELECT, DELETE, and INSERT privilegesset to public.

– Recovery account. The account name is assigned with the HS_FDS_RECOVERY_ACCOUNT parameter.

– Recovery account password. The password is assigned with the HS_FDS_RECOVERY_PWD parameter.

■ READ_ONLY provides read access to the non-Oracle database.

■ SINGLE_SITE provides read and write access to the non-Oracle database. However,the gateway cannot participate in distributed updates.

■ READ_ONLY_AUTOCOMMIT provides read only access to the non-Oracle database thatdoes not use logging.

■ SINGLE_SITE_AUTOCOMMIT provides read and write access to the non-Oracledatabase without logging. The gateway cannot participate in distributed updates.Moreover, any update to the non-Oracle database is committed immediately.

IFILE

Use the IFILE initialization parameter to embed another initialization file within thecurrent initialization file. The value should be an absolute path and should not containenvironment variables. The three levels of nesting limit do not apply.


Default Value COMMIT_CONFIRM

Range of Values COMMIT_CONFIRM, READ_ONLY, SINGLE_SITE, READ_ONLY_AUTOCOMMIT, SINGLE_SITE_AUTOCOMMIT


Default value None

Range of values Valid parameter file names

See Also: Oracle Database Reference



HS_FDS_TIMESTAMP_MAPPING

If set to CHAR, then non-oracle target timestamp would be mapped to CHAR(26). If set toDATE, then non-Oracle target timestamp would be mapped to Oracle date. If set toTIMESTAMP, then non-Oracle target timestamp would be mapped to Oracle timestamp.

HS_FDS_DATE_MAPPING

If set to CHAR, then non-oracle target date would be mapped to CHAR(10). If set to DATE,then non-Oracle target date would be mapped to Oracle date.

HS_FDS_CONNECT_INFO

HS_FDS_CONNECT_INFO that describes the connection to the non-Oracle system.

The default initialization parameter file already has an entry for this parameter. Thesyntax for HS_FDS_CONNECT_INFO for the gateway is as follows:

HS_FDS_CONNECT_INFO=host_name:port_number/database_name

where, host_name is the host name or IP address of the machine hosting the Sybasedatabase, port_number is the port number of the Sybase database server, anddatabase_name is the Sybase database name.

This release supports IPv6 format, so you can enter IPv6 format in place of hostname,but you need to wrap square brackets around the IPv6 specification.

For example,

HS_FDS_CONNECT_INFO=[2001:0db8:20c:f1ff:fec6:38af]:port_number/…


Default Value DATE

Range of Values CHAR|DATE|TIMESTAMP

Syntax HS_FDS_TIMESTAMP_MAPPING={CHAR|DATE|TIMESTAMP}


Default Value DATE

Range of Values DATE|CHAR

Syntax HS_FDS_DATE_MAPPING={DATE|CHAR}


Default Value None

Range of Values Not applicable



HS_FDS_PROC_IS_FUNC

Enables return values from functions. By default, all stored procedures and functionsdo not return a return value to the user.

HS_FDS_RECOVERY_ACCOUNT

Specifies the name of the recovery account used for the commit-confirm transactionmodel. An account with user name and password must be set up at the non-Oraclesystem. For more information about the commit-confirm model, see the HS_TRANSACTION_MODEL parameter.

The name of the recovery account is case sensitive.

HS_FDS_RECOVERY_PWD

Specifies the password of the recovery account used for the commit-confirmtransaction model set up at the non-Oracle system. For more information about thecommit-confirm model, see the HS_TRANSACTION_MODEL parameter.

The name of the password of the recovery account is case sensitive.

HS_FDS_RESULTSET_SUPPORT

Enables result sets to be returned from stored procedures. By default, all storedprocedures do not return a result set to the user.


Default Value FALSE

Range of Values TRUE, FALSE

Note: If you set this initialization parameter, you must change thesyntax of the procedure execute statement for all existing storedprocedures to handle return values.


Default Value RECOVER

Range of values Any valid user ID


Default Value RECOVER

Range of values Any valid password


Default Value FALSE




HS_FDS_TRACE_LEVEL

Specifies whether error tracing is turned on or off for gateway connectivity.

The following values are valid:

■ OFF disables the tracing of error messages.

■ ON enables the tracing of error messages that occur when you encounter problems.The results are written by default to a gateway log file in LOG directory where thegateway is installed.

■ DEBUG enables the tracing of detailed error messages that can be used fordebugging.

HS_FDS_TRANSACTION_LOG

Specifies the name of the table created in the non-Oracle system for loggingtransactions. For more information about the transaction model, see the HS_TRANSACTION_MODEL parameter.

HS_FDS_FETCH_ROWS

HS_FDS_FETCH_ROWS specifies the fetch array size. This is the number of rows to befetched from the non-Oracle database and to return to Oracle database at one time.This parameter will be affected by the HS_RPC_FETCH_SIZE and HS_RPC_FETCH_REBLOCKING parameters.

Note: If you set this initialization parameter, you must do thefollowing:

■ Change the syntax of the procedure execute statement for allexisting stored procedures, to handle result sets

■ Work in the sequential mode of Heterogeneous Services


Default Value OFF

Range of values OFF, ON, DEBUG


Default Value HS_TRANSACTION_LOG

Range of Values Any valid table name


Default Value 100

Range of Values Any integer between 1 and 1000

Syntax HS_FDS_FETCH_ROWS=num



HS_FDS_QUOTE_IDENTIFIER

HS_FDS_QUOTE_IDENTIFIER overrides the target’s ability to support quote identifierdepending on the value provided. The default value is TRUE for Sybase.

HS_IDLE_TIMEOUT

This feature is only available for Oracle Net TCP protocol. When there is no activity fora connected gateway session for this specified time period, the gateway session wouldbe terminated automatically with pending update (if any) rolled back.

HS_NLS_LENGTH_SEMANTICS

This release of gateway has Character Semantics functionality equivalent to the OracleDatabase Character Semantics, that is, NLS_LENGTH_SEMANTICS. When HS_NLS_LENGTH_SEMANTICS is set to CHAR, the (VAR)CHAR columns of Sybase database are to beinterpreted as having CHAR semantics. The only situation the gateway does not honorthe HS_NLS_LENGTH_SEMANTICS=CHAR setting is when both Oracle database and thegateway are on the same multi-byte character set.

HS_KEEP_REMOTE_COLUMN_SIZE


Default Value TRUE for Sybase

Range of Values TRUE | FALSE

Syntax HS_FDS_QUOTE_IDENTIFIER = { TRUE | FALSE }


Default Value 0 (no timeout)

Range of Values 0-9999 (minutes)

Syntax HS_IDLE_TIMEOUT=num


Default Value BYTE

Range of Values BYTE | CHAR

Syntax HS_NLS_LENGTH_SEMANTICS = { BYTE | CHAR }


Default Value OFF

Range of Values OFF | LOCAL | REMOTE | ALL

Syntax HS_KEEP_REMOTE_COLUMN_SIZE = OFF | LOCAL |REMOTE |ALL

Parameter type String



HS_KEEP_REMOTE_COLUMN_SIZE specifies whether to suppress ratio expansion whencomputing the length of (VAR)CHAR datatypes during data conversion from thenon-Oracle database to the gateway, and then to the Oracle database. When it is set toREMOTE, the expansion is suppressed between the non-Oracle database and thegateway. When it is set to LOCAL, the expansion is suppressed between the gatewayand the Oracle database. When it is set to ALL, the expansion is suppressed from thenon-Oracle database to the Oracle database.

When the parameter is set, the expansion is suppressed when reporting the remotecolumn size, calculating the implicit resulting buffer size, and instantiating in the localOracle database. This has effect only for remote column size from non-Oracle databaseto Oracle database. If the gateway runs on Windows and HS_LANGUAGE=AL32UTF8, thenyou must not specify this parameter, as it would influence other ratio relatedparameter operation. It has no effect for calculating ratio for data moving from Oracledatabase to non-Oracle database through gateway during INSERT, UPDATE, or DELETE.

HS_FDS_REMOTE_DB_CHARSET

This parameter is valid only when HS_LANGUAGE is set to AL32UTF8 and the gatewayruns on Windows. As more Oracle databases and non-Oracle databases use Unicode asdatabase character sets, it is preferable to also run the gateway in Unicode characterset. To do so, you must set HS_LANGUAGE=AL32UTF8. However, when the gateway runson Windows, the Microsoft ODBC Driver Manager interface can exchange data only inthe double-byte character set, UCS2. This results in extra ratio expansion of describedbuffer and column sizes. To compensate, the gateway can re-adjust the column size ifHS_FDS_REMOTE_DB_CHARSET is set to the corresponding non-Oracle database characterset. For example, HS_FDS_REMOTE_DB_CHARSET=KO16KSC5601.

HS_FDS_SUPPORT_STATISTICS

We gather statistics from the non-Oracle database by default. You can choose to disablethe gathering of remote database statistics by setting the HS_FDS_SUPPORT_STATISTICSparameter to FALSE.

HS_FDS_RSET_RETURN_ROWCOUNT


Default Value None

Range of values Not applicable

Syntax HS_FDS_REMOTE_DB_CHARSET


Default Value TRUE

Range of values {TRUE|FALSE}

Syntax HS_FDS_SUPPORT_STATISTICS= {TRUE|FALSE}


Default Value FALSE



When set to TRUE, the gateway returns the row counts of DML statements that areexecuted inside a stored procedure. The row count is returned as a single row, singlecolumn result set of type signed integer.

When set to FALSE, the gateway skips the row counts of DML statements that areexecuted inside a stored procedure. This is the default behavior, and it is the behaviorof 11.1 and older gateways.

HS_FDS_SQLLEN_INTERPRETATION

This parameter is only valid for 64 bit platforms. ODBC standard specifies SQLLEN (ofinternal ODBC construct) being 64 bit on 64 bit platforms, but some ODBC drivermanagers and drivers violate this convention, and implement it as 32 bit. In order forthe gateway to compensate their behavior, you need to specify HS_FDS_SQLLEN_INTERPRETATION=32 if you use these types of driver managers and driver.

HS_FDS_REPORT_REAL_AS_DOUBLE

Enables Oracle Database Gateway for Sybase treat SINGLE FLOAT PRECISION fields asDOUBLE FLOAT PRECISION fields.

HS_FDS_ARRAY_EXEC

If set to TRUE, the gateway will use array operations for insert, update, deletestatements containing binds against the remote data source. The array size isdetermined by the value of the HS_FDS_FETCH_ROWS init parameter.


Syntax HS_FDS_RSET_RETURN_ROWCOUNT= {TRUE|FALSE}


Default Value 64

Range of values {64|32}

Syntax HS_FDS_SQLLEN_INTERPRETATION= {64|32}


Default Value FALSE



Default Value TRUE


Syntax HS_FDS_ARRAY_EXEC= {TRUE|FALSE}




If set to FALSE, the gateway will not use array operations for insert, update, and deletestatements. Instead, a single statement will be issued for every value.

Index-1

Index

AALTER statement, B-1Arithmetic operators, B-2

BBINARY data type, A-1BIT data type, A-1

CCase rules, 2-8Case studies, 3-1Chained mode, 2-7CHAR data type, A-1character sets

Heterogeneous Services, D-5COMMIT

restrictions, 2-11Commit point site, 2-11Comparison operators, B-3CONCAT operator, 2-15CONNECT BY clause, 2-12COPY command, 2-13CREATE statement, B-1Cursor loops

restrictions, 2-11

DData definition language, B-1Data dictionary

views, C-2Data type

BINARY, A-1BIT, A-1CHAR, A-1conversion, 2-9DATE, A-1DATETIME, A-1DECIMAL, A-1FLOAT, A-1IMAGE, A-1INTEGER, A-1LONG, A-1LONG RAW, A-1

MONEY, A-1NUMBER, A-1NUMERIC, A-1RAW, A-1REAL, A-1SMALL DATETIME, A-1SMALL MONEY, A-1SMALLINT, A-1TEXT, A-1TINYINT, A-2VARBINARY, 2-14, A-2VARCHAR, A-2VARCHAR2, A-2

DATE data type, A-1DATETIME data type, A-1DDL statement, 2-12DECIMAL data type, A-1DELETE statement, 3-5, B-1, B-2demonstration build SQL script, 3-2Demonstration files, 3-2Demonstration tables, 3-2Demonstration tables build SQL script, 3-2describe cache high water mark

definition, D-5DROP statement, B-1

EEncrypted format login, 2-14Error messages

error tracing, D-11Errors

ORA-02070, 2-11Executing Stored Procedures, 3-6

Ffetch array size, with HS_FDS_FETCH_ROWS, D-11FLOAT data type, A-1Functions in SQL, 2-2

GGateway

case studies, 3-1data dictionary tables, C-1

Index-2

pass-through feature, 2-1supported functions, B-1supported SQL syntax, B-1

globalization supportHeterogeneous Services, D-5

GRANT statement, B-1Group functions, B-3

HHeterogeneous Services

defining maximum number of open cursors, D-6optimizing data transfer, D-7setting global name, D-4specifying cache high water mark, D-5tuning internal data buffering, D-7tuning LONG data transfer, D-6

Hexadecimal notation, 2-8HS_CALL_NAME initialization parameter, D-3HS_DB_NAME initialization parameter, D-4HS_DESCRIBE_CACHE_HWM initialization

parameter, D-5HS_FDS_CONNECT_INFO, D-9HS_FDS_FETCH_ROWS parameter, D-11HS_FDS_PROC_IS_FUNC initialization

parameter, D-10HS_FDS_RECOVERY_PWD initialization

parameter, D-14HS_FDS_RESULTSET_SUPPORT initialization

parameter, D-10HS_FDS_TRACE_LEVEL initialization

parameter, D-11enabling agent tracing, D-2

HS_FDS_TRANSACTION_LOG initializationparameter, D-11

HS_IDLE_TIMEOUT initialization parameter, D-12HS_KEEP_REMOTE_COLUMN_SIZE initialization

parameter, D-13HS_LANGUAGE initialization parameter, D-5HS_LONG_PIECE_TRANSFER_SIZE initialization

parameter, D-6HS_NLS_LENGTH_SEMANTICS initialization

parameter, D-12HS_OPEN_CURSORS initialization parameter, D-6HS_RPC_FETCH_REBLOCKING initialization

parameter, D-7HS_RPC_FETCH_SIZE initialization parameter, D-7HS_TIME_ZONE initialization parameter, D-7

IIFILE initialization parameter, D-8IMAGE data type, A-1Initialization parameter file

customizing, D-1INSERT statement, 2-12, 3-5, B-1, B-2INTEGER data type, A-1

KKnown restrictions, 2-10

LLocking, database, 2-10LONG data type, A-1LONG RAW data type, A-1

MMONEY data type, A-1

NNULL values, 2-7NUMBER data type, A-1NUMERIC data type, A-1NVL function, 3-5

OObjects, naming rules, 2-7ORA-02070, 2-11

Pparameters

gateway initialization fileHS_FDS_FETCH_ROWS, D-11

Passing commands to database, 2-12Pass-Through Feature, 3-6Pass-through feature, 2-12PL/SQL, 2-15

RRAW data type, A-1REAL data type, A-1remote functions

referenced in SQL statements, D-3ROLLBACK

restrictions, 2-11ROWID, 2-12

Ssavepoint support, 2-11SELECT statement, 3-6, B-1, C-1SMALL DATETIME data type, A-1SMALLINT data type, A-1Stored procedures, 2-11, 2-15

running in chained mode, 2-7Stored procedures in SQL Server, 2-2String functions, B-3SUM function, 3-5

TTEXT data type, A-1TINYINT data type, A-2Transaction modes, 2-7transactional capability, 2-11transactional integrity, 2-11TRUNCATE statement, B-1

Index-3

Two-phase commit, 2-11

UUPDATE statement, 3-5, 3-6, B-2

VVARBINARY data type, 2-14, A-2VARCHAR data type, A-2VARCHAR2 data type, A-2

WWHERE CURRENT OF clause, 2-12

Index-4

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