1.Concepts of NonStop SQL/MXIntroduction to SQL/MX MetadataTechnical white paperTable of contentsIntroduction ..................................................................................................................................2 Intended audience ....................................................................................................................2 Examples .................................................................................................................................2Introduction to SQL/MX metadata ..................................................................................................2 Metadata .................................................................................................................................2 The system catalog ....................................................................................................................3 User catalogs ...........................................................................................................................3 Exploring object definitions ........................................................................................................4 Commands for showing row layout .............................................................................................4 Commands for showing object definitions ....................................................................................5Metadata views ............................................................................................................................7 ZZSYSSCHEMAS ......................................................................................................................8 ZZSYSTABLES ...........................................................................................................................8 ZZTABLES and ZZALLTABLES ......................................................................................................8 ZZPARTITIONS .........................................................................................................................8 ZZPRIVILEGES ..........................................................................................................................9The mxschema script .....................................................................................................................9Legal status ..............................................................................................................................9Catalog and schema options ......................................................................................................9Action options ..........................................................................................................................9Configuration options ..............................................................................................................10Online help ............................................................................................................................11Conclusion .................................................................................................................................12References .................................................................................................................................12Other interesting reads ................................................................................................................12

2. IntroductionWhen customers migrate Oracle applications to NonStop SQL/MX, DBAs with an Oracle background may feel a bitlost, because both products have their specific solutions to common practices such as disk storage and user access.This article is one in a series, inspired by the Oracle Database: Concepts 11g Release 2 manual, and tries to explainsome of those differences in implementation. Other articles will address other differences.Intended audienceThis article is written for DBAs and developers who know Oracle and want to learn about NonStop SQL/MX. It mayalso be useful for people who know NonStop and would like to know about similarities and differences between thetwo products.ExamplesIn this article, the Oracle examples use the SQL*Plus command interface and the NonStop SQL/MX examples aremade using the mxci equivalent. The SQL*Plus commands are indicated by the SQL> prompt; those in mxci areindicated by >>.Introduction to SQL/MX metadataOracle maintains a set of read-only reference tables and views for each Oracle database that it calls the datadictionary. NonStop SQL/MX maintains a set of read-only reference tables that it calls the catalog, or more broadly,the metadata tables. Both products provide read-only access to these tables using the SQL language. Any directmodifications, however, are prohibited to users. Instead, the metadata is updated as the result of Data DefinitionLanguage (DDL) operations such as CREATE TABLE, CREATE VIEW, ALTER TABLE, and DROP INDEX statements.MetadataNonStop SQL/MX stores metadata for all objects in designated SQL/MX tables that are automatically maintained asa result of DDL operations or when table statistics are updated by the UPDATE STATISTICS 1 command. Other tablesmay contain information about the status of certain DDL operations, such as on-line movement of data, the fastcopyutility, and (online) populating of indexes.A complete description of all the metadata tables can be found in Chapter 10 of the SQL/MX Reference Manual,which can be found through the technical documents site: http://www.hp.com/go/nonstop-docs.SQL/MX metadata is structured in catalogs and schemas, which are used to logically group definitions of databases.Most customers use multiple catalogs and each catalog can have multiple schemas.Part of the metadata is contained in other locations on a system, such as the file labels and resource forks. Thatinformation, however, is for use by internal, low-level SQL/MX routines only and typically is not accessible via theSQL language but instead, when applicable, via dedicated tools.1UPDATE STATISTICS is similar in function to the Oracle ANALYZE TABLE command; it gathers per-column statistics that are used by the SQL Querycompiler to determine an optimal query execution plan.2 3. The system catalogIn Oracle, each database includes a dedicated tablespace, called SYSTEM, which stores dictionary tables and is thedefault location for user definitions. NonStop SQL/MX is quite different.Every NonStop node where SQL/MX is installed has exactly one system catalog. It contains five schemas thatcollectively hold the systems definitions. It cannot be used to store user definitions.In this case system refers to the local node instead of an Oracle instance. System-wide defaults are maintained inthe SYSTEM_DEFAULTS table in the SYSTEM_DEFAULTS_SCHEMA.Each node in a NonStop EXPAND 2 cluster network has its own SQL/MX system catalog, if SQL/MX is installed onthat node. The system catalog is created and automatically named when SQL/MX is installed. The unique systemname, as used by EXPAND, is used as a suffix to ensure system catalog names are consistent and yet unique acrossthe network. For example, the system catalog for the node named NSKIT11 would be calledNONSTOP_SQLMX_NSKIT11.User catalogsUser catalogs and schemas need to be created before tables and other user objects can be defined. A usercatalog contains one system schema and one or more user schemas. The system schema,DEFINITION_SCHEMA_VERSION_3000 3, includes the tables that contain the definitions of all the objects in thecatalog. Each user schema contains user data tables as well as metadata tables that contain database statisticsfor these user tables.Figure 1 shows how catalogs, schemas, and tables are related. It shows a system schema, calledDEFINITION_SCHEMA_VERSION_3000, and two user schemas, one for test, and another for production. The userschemas share the OBJECTS and ACCESS_PATHS metadata tables. Each schema has its own HISTOGRAMS andHISTOGRAM_INTERVALS table and, if the mxschema script has been executed, its own copy of the convenienceviews such as ZZTABLES. The mxschema script is discussed later in this article.Figure 1: Catalog object hierarchy2The Expand product allows the distribution of database data across geographically separated systems, up to 255 servers in a network. This istransparent to the applications, which only refer to the tables by their ANSI table names as if all data is local.3This is the version as of SQL/MX release 3.0. Previous releases used version number 1200. 3 4. Exploring object definitionsMany DBAs use command line interfaces such as SQL*Plus and mxci to get information about the definitions ofdatabase objects. Typical questions are: What is the layout of this table? and what does the DDL look like?. Thesections below briefly explain how to answer these questions.Commands for showing row layoutIn SQL*Plus, the desc command can be used to show which columns are present in a table definition. In SQL/MX, theinvoke command has a similar function. Example 1 shows the output side by side.Example 1: Obtaining a record layoutOracle SQL*Plus commandNonStop SQL/MX mxci commandSQL> desc emp2m; >>invoke emp2m;NameNull?Type--------- ------------------ -- Definition of table FRANS.HPJ.EMP2MEMPNO NOT NULL NUMBER(38)-- Definition current Wed May 11 07:14:12 2011UPDATABLE NOT NULL NUMBER(38)(ENAME NOT NULL CHAR(16) JOBNOT NULL CHAR(20) SALEMPNOINT NO DEFAULT NOT NULL NOT DROPPABLENOT NULL NUMBER(38), UPDATABLEINT NO DEFAULT NOT NULL NOT DROPPABLEDEPTNONOT NULL NUMBER(38), ENAMECHAR(16) CHARACTER SET ISO88591 COLLATEDMY NOT NULL CHAR(80) DEFAULT NO DEFAULT NOT NULL NOT DROPPABLE , JOBCHAR(20) CHARACTER SET ISO88591 COLLATESQL> DEFAULT NO DEFAULT NOT NULL NOT DROPPABLE , SALINT NO DEFAULT NOT NULL NOT DROPPABLE , DEPTNO INT NO DEFAULT NOT NULL NOT DROPPABLE , DMYCHAR(80) CHARACTER SET ISO88591 COLLATE DEFAULT NO DEFAULT NOT NULL NOT DROPPABLE ) --- SQL operation complete. >>4 5. Commands for showing object definitionsIn SQL*Plus, DBAs use the GET_DDL function of the DBMS_METADATA package to get the definitions of an object. Thefunction requires the object type (for example, TABLE) and the name. The command shown in example 2 is used on atable called EMP2M. The output reflects the full table name (SYSTEM.EMP2M) and its defaults and storage parameters.Example 2: Using the Oracle DBMS_METADATA.GET_DDL functionSQL> select dbms_metadata.get_ddl(TABLE,EMP2M) from DUAL;DBMS_METADATA.GET_DDL(TABLE,EMP2M)-------------------------------------------------------------------------------CREATE TABLE "SYSTEM"."EMP2M"("EMPNO" NUMBER(*,0) NOT NULL ENABLE, "UPDATABLE" NUMBER(*,0) NOT NULL ENABLE, "ENAME" CHAR(16) NOT NULL ENABLE, "JOB" CHAR(20) NOT NULL ENABLE, "SAL" NUMBER(*,0) NOT NULL ENABLE, "DEPTNO" NUMBER(*,0) NOT NULL ENABLE, "DMY" CHAR(80) NOT NULL ENABLE, PRIMARY KEY ("EMPNO")USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULTCELL_FLASH_CACHE DEFAULT)TABLESPACE "SYSTEM"ENABLE) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING STORAGE(INITIAL 65536 NEXT1048576 MINEXTENTS 1 MAXEXTENTS 2147483645PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DEFAULTCELL_FLASH_CACHE DEFAULT)TABLESPACE "SYSTEM"SQL>NonStop SQL/MX uses a similar function, called SHOWDDL, which requires only the object name. Example 3 and 4shows similar output as that produced by DBMS_METADATA.GET_DDL. As in SQL*Plus, the command listsinformation about specific storage locations as well as the index and column definitions.5 6. Example 3: Using SHOWDDL to obtain DDL information>>showddl emp2m;CREATE TABLE FRANS.HPJ.EMP2M (EMPNO INT NO DEFAULT -- NOT NULL NOT DROPPABLE, UPDATABLE INT NO DEFAULT -- NOT NULL NOT DROPPABLE, ENAME CHAR(16) CHARACTER SET ISO88591 COLLATE DEFAULT NO DEFAULT -- NOT NULL NOT DROPPABLE, JOB CHAR(20) CHARACTER SET ISO88591 COLLATE DEFAULT NO DEFAULT -- NOT NULL NOT DROPPABLE, SAL INT NO DEFAULT -- NOT NULL NOT DROPPABLE, DEPTNOINT NO DEFAULT -- NOT NULL NOT DROPPABLE, DMY CHAR(80) CHARACTER SET ISO88591 COLLATE DEFAULT NO DEFAULT -- NOT NULL NOT DROPPABLE, CONSTRAINT FRANS.HPJ.EMP2M_898213697_6493 PRIMARY KEY (EMPNO ASC) NOT DROPPABLE, CONSTRAINT FRANS.HPJ.EMP2M_948592697_6493 CHECK (FRANS.HPJ.EMP2M.EMPNO IS NOT NULL ANDFRANS.HPJ.EMP2M.UPDATABLE IS NOT NULL AND FRANS.HPJ.EMP2M.ENAME IS NOT NULL ANDFRANS.HPJ.EMP2M.JOB IS NOT NULL AND FRANS.HPJ.EMP2M.SAL IS NOT NULL AND FRANS.HPJ.EMP2M.DEPTNOIS NOT NULLAND FRANS.HPJ.EMP2M.DMY IS NOT NULL) NOT DROPPABLE)LOCATION NSKIT11.$DATA08.ZSDFJ006.N5G48T00NAME NSKIT11_DATA08_ZSDFJ006_N5G48T00ATTRIBUTES BLOCKSIZE 4096, EXTENT (50000, 50000) HASH PARTITION(ADD LOCATION NSKIT11.$DATA09.ZSDFJ006.FDH48T00NAME NSKIT11_DATA09_ZSDFJ006_FDH48T00EXTENT (50000, 50000), ADD LOCATION NSKIT11.$DATA10.ZSDFJ006.HHJ48T00NAME NSKIT11_DATA10_ZSDFJ006_HHJ48T00EXTENT (50000, 50000), ADD LOCATION NSKIT11.$DATA07.ZSDFJ006.S8J48T00NAME NSKIT11_DATA07_ZSDFJ006_S8J48T00EXTENT (50000, 50000))STORE BY (EMPNO ASC);CREATE INDEX EMP2M_IX ON FRANS.HPJ.EMP2M (UPDATABLE ASC)LOCATION NSKIT11.$DATA08.ZSDFJ006.Q9W1WV00NAME NSKIT11_DATA08_ZSDFJ006_Q9W1WV00ATTRIBUTES BLOCKSIZE 4096, EXTENT (50000, 50000), MAXEXTENTS 400PARTITION (ADD FIRST KEY (500001)LOCATION NSKIT11.$DATA09.ZSDFJ006.QJX1WV00NAME NSKIT11_DATA09_ZSDFJ006_QJX1WV00EXTENT (50000, 50000) MAXEXTENTS 400, ADD FIRST KEY (1000001)LOCATION NSKIT11.$DATA10.ZSDFJ006.STZ1WV00NAME NSKIT11_DATA10_ZSDFJ006_STZ1WV00EXTENT (50000, 50000) MAXEXTENTS 400, ADD FIRST KEY (1500001)LOCATION NSKIT11.$DATA07.ZSDFJ006.SP11WV00NAME NSKIT11_DATA07_ZSDFJ006_SP11WV00EXTENT (50000, 50000) MAXEXTENTS 400);--- SQL operation complete.>>6 7. SHOWDDL can also be used to obtain view definitions, as is shown in example 4 for the DUAL view in SQL/MX.Example 4: SHOWDDL command applied to views>>showddl dual;CREATE VIEW FRANS.HPJ.DUAL ASSELECT D.D FROM (VALUES (0)) D(D) ;--- SQL operation complete.>>Metadata viewsAs the descriptions of the NonStop SQL/MX system tables in the earlier sections make clear, a query to retrieve allthe table names of a schema involves joining multiple catalog tables. To simplify such queries, the NonStopAdvanced Technology Center (ATC) designed a set of convenience views on the system metadata. These views giveeasy access to the metadata on a schema level because they are part of the user schema. Convenience views arecreated by a shell script called mxschema. The script and its options are described later in this article in Themxschema script.Oracles dictionary views are grouped in sets, prefixed by ALL_, DBA_, and USER_; according to their use. Theconvenience views for SQL/MX, except the special DUAL view, are prefixed with ZZ. This query, againstZZVIEWS, returns the list of views in the current schema.Example 5: SQL/MX metadata convenience views>>select view_name from zzviews;VIEW_NAME------------------------------DUAL ZZALLTABLESZZCOLUMNSZZCONSTRAINTSZZIDENTITIESZZINDEXESZZPARTITIONSZZPRIVILEGESZZPROCEDURESZZSCHEMAZZSTATISTICSZZSYSSCHEMASZZSYSTABLESZZTABLESZZTABLES_DISTHISTZZVIEWS--- 16 row(s) selected.>>The SQL/MX metadata views show data for the current schema except for the ZZSYSSCHEMAS and ZZSYSTABLESviews, which show information at the system level. The next sections describe commonly used views.Important note: Some of the fields have been deliberately truncated in the view definitions to allow for an easyreadable overview on a terminal screen. This does not mean that SQL/MX has truncated the names in any way; it justmeans that the view may not show the complete names if they are very long.7 8. ZZSYSSCHEMASThis view shows the full catalog and schema name as well as the schema owner and metadata storage locationinformation for all the catalog and schemas on the system. It provides an overview similar to the list option of themxschema shell script.ZZSYSTABLESThis view shows the names of the system-wide DEFAULTS table, the names of the tables in the system-wideSYSTEM_SCHEMA, and the names of the metadata tables in the current user catalog.Example 6: The ZZSYSTABLES view>>select * from zzsystables; SYSTABLE_NAME-----------------------------------------------------------------------NONSTOP_SQLMX_NSKIT11.SYSTEM_DEFAULTS_SCHEMA.SYSTEM_DEFAULTSNONSTOP_SQLMX_NSKIT11.SYSTEM_SCHEMA.CATSYSNONSTOP_SQLMX_NSKIT11.SYSTEM_SCHEMA.CAT_REFERENCESNONSTOP_SQLMX_NSKIT11.SYSTEM_SCHEMA.SCHEMATANONSTOP_SQLMX_NSKIT11.SYSTEM_SCHEMA.SCHEMA_REPLICASDEFINITION_SCHEMA_VERSION_3000.ACCESS_PATHSDEFINITION_SCHEMA_VERSION_3000.ACCESS_PATH_COLS--- 42 row(s) selected.>>Note:The system-wide table names have three-part table names (catalog name,schema name, and table name), but the names of tables in the current schemaonly contain the name of the DEFINITION_SCHEMA and the table. The reasonfor this is the intended use of this view: to copy and paste the name in a DBAmetadata query.ZZTABLES and ZZALLTABLESZZTABLES provides information about the individual table, such as the size of the row, the block size, the size of thekey, the partition type (hash, range, or not partitioned), and also the time when the last statistics were collected.The ZZALLTABLES view is helpful to customers who use SQL/MX to access tables managed by the previous version ofNonStop SQL, called SQL/MP, which uses a different file system structure. These tables can be used by programs asif they were native tables; however, the SQL/MX metadata contains only a reference to metadata in SQL/MP.ZZPARTITIONSZZPARTITIONS shows how the tables and indexes are distributed over the available storage and, where applicable,over the various nodes in a NonStop cluster. When statistics have been updated, the view also shows the partitionsize and the index levels of the B-tree indexes as well as the number of non-empty blocks.8 9. ZZPRIVILEGESThis view shows, per object, such as table view or Stored Procedure, the privileges that are granted to users. Theusers (the grantor and grantees) are NonStop OS users, displayed in the form GROUP_NAME.USER_NAME. Notethat users may have alias names for the GROUP.USER name. For example, user jane could map to the full nameADMINS.JANE.The mxschema scriptThe metadata views are shorthand convenience views on tables in the SQL/MX catalog that allow a user to entersimple SQL queries rather than creating complex queries to join multiple tables. Every change in the metadata as aresult of DDL actions will automatically be present when the views are used in queries.The views are created by running a shell script called mxschema.Legal statusThis script is provided by HP as-is and without warranty, and it can be modified by users if so desired. The full legaltext is available when the script is called with the X option.Catalog and schema optionsThe script requires a catalog and schema name for all except the list option which is described below. The catalogname is passed using the C option and the schema name is passed using the S option.Action optionsThe action options are specified in lower case and invoke the following functions:Help (-h)is the default option and shows the full list of options with a short explanation. When errors occur, such as an invalid or missing option, these will be displayed along with the help text. Example 8 shows an example of this help text.List (-l)produces an overview of all catalogs and schemas on the system. Example 7 shows an example of the schemas in catalog FRANS and those in the system catalog. Note that the long names may be truncated in order to produce a report that fits on an 80 column screen.Create (-c)is used to create a new catalog (when the S option is not present) or to create a new schema and, following, the convenience views. The views can also be created in an existing schema using this option. Note that in that case, the CREATE SCHEMA command will return an error that can be ignored.Delete (-d)is used to drop the views that were created by this script or an earlier version of it. The script attempts to drop the views it would create in its current version. Therefore errors might occur if a new version of the script is executed against an older version of the views. However, these errors can safely be ignored. Note that the -d option does not drop the DUAL view, because DUAL may be used in user programs and dropping it will invalidate these user programs.Refresh (-r) is used to replace an older version of the views by a newer version. Refresh executes the delete option, followed by the create option. The expected errors 1022, Schema already exists and 1055, View DUAL already exists error can be ignored. 9 10. Example 7: Output of the mxschema list option ~> mxschema -l mxschema Version 10.0 May 16, 2011. Listing of SQL/MX schemas on NSKIT11. CATALOG_NAME VOLUMESCHEMA_NAMESCHEMA_SUBVOL ------------------------------------------------------------- ------------ FRANS$DATA01 DEFINITION_SCHEMA_VERSION_300ZSD99Q2D FRANS$DATA01 PERF ZSDFJ000 FRANS$DATA01 MX30 ZSDFJ001 FRANS$DATA01 HPJZSDFJ006 NONSTOP_SQLMX_NSKIT11$DSMSCM SYSTEM_SCHEMAZSD0 NONSTOP_SQLMX_NSKIT11$DSMSCM MXCS_SCHEMAZSD1 NONSTOP_SQLMX_NSKIT11$DSMSCM DEFINITION_SCHEMA_VERSION_300ZSD4KFDD NONSTOP_SQLMX_NSKIT11$DSMSCM SYSTEM_SQLJ_SCHEMA ZSD591VH NONSTOP_SQLMX_NSKIT11$DSMSCM SYSTEM_DEFAULTS_SCHEMA ZSD5K7KH Configuration options When a catalog or schema is created, additional configuration options can be passed to the script. These configuration options, just like the catalog (C) and schema (S) options described earlier, are given in uppercase. Location (-L) sets the Guardian subvolume 4, used when a new schema is created. The location may not exceed 8 characters and must start with the letters ZSD. Objects for this schema will be stored on disk volumes using this subvolume name. Volume (-V) sets the Guardian volume default for the duration of the script. By default, SQL/MX creates metadata tables on the OS users default Guardian volume. The V option changes the default volume for the duration of the script so that the metadata tables and the views will be created on the volume of choice. User (-U) group.usergrants SELECT access to the metadata views to this user. The user name is in the form GROUPNAME.USERNAME (for example ADMINS.JOE). By default, the script grants SELECT access to PUBLIC, so that every user can query the metadata. The DUAL view will always be readable by everyone. 4 The LOCATION clause defines the subvolume for the schema objects when a schema is created. A LOCATION can also be given when user objects, like tables, are created. For these user objects however, the LOCATION refers to disk VOLUMEs.10 11. Online helpCalling mxschema with the h option, or just by itself, shows an overview of all the options with a short explanation.Example 8: mxschema help text~> mxschema -hmxschema: valid options are XlcrdhC:S:V:L:U:m:--Version 10.0 May 16, 2011List and create SQL/MX Schemas and create convenience viewsSupported options are:h = This helpl = List schema information.c = create a new catalog or a schema in an already existing catalog d = deleter = refreshC = Set CATALOG to useS = Set SCHEMA to use. When not set, try to create catalogL = Set the LOCATION when creating a schema. Must start with ZSD and not exceed 8 charactersV = Set the default VOLUME when creating a catalog or schema. The $ sign is optional but whenspecified must be escaped.The V option sets the _DEFAULTS define prior to invoking mxci.U = Optional USER.GROUP name that gets granted SELECT access to the created metadata views. Bydefault, mxschema will grant access to PUBLICd = Delete the metadata views. This option is used when upgrading the SQL/MX metadata from e.g.Version 1200 to Version 3000. NOTE: The DUAL view will not be dropped.r = Refresh (delete the views and then create the views). This option is used when new viewshave been introduced and an existing schema wants to have them installed.NOTE: The DUAL view will not be refreshed.m = alternative location of mxci. Currently set to: /usr/tandem/sqlmx/bin/mxciX = DISCLAIMER11 12. ConclusionThis article presented an overview of the metadata in NonStop SQL, which is organized in catalogs, schemas, andother objects. This is one level more than Oracle, which defines only schemas and other objects. Both Oracle andNonStop SQL/MX allow users to query the metadata tables using the SQL language, and both products provide away to simplify this task. Oracle uses a dedicated package; SQL/MX uses a set of convenience views. The creationof the convenience views is done via a separate shell script, called mxschema, also described.ReferencesOracle Database Concepts 11g Release 2 (11.2)http://www.oracle.com/pls/db112/to_pdf?pathname=server.112/e16508.pdfNonStop SQL/MX 3.x Reference Manualhttp://bizsupport2.austin.hp.com/bc/docs/support/SupportManual/c02732022/c02732022.pdfUsing NonStop SQL/MX subscribe to Monitor Catalog OperationsThe Connection magazine, March/April 2010.http://storage.synchost.com/eanderson/2010/The%20Connection/Connect_Mar-Apr%202010-web.pdfOther interesting readsClarifying HP NonStop server new terminologyhttp://h71028.www7.hp.com/ERC/downloads/4AA0-3158ENW.pdfTo know more about NonStop SQL/MX, visit www.hp.com/go/NonStop Copyright 2011 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. Theonly warranties for HP products and services are set forth in the express warranty statements accompanying such products and services.Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors oromissions contained herein.Oracle is a registered trademark of Oracle and/or its affiliates.4AA3-6539ENW, Created October 2011