teradata oracle comparision

1

Comparison between Oracle and Teradata

Center of Excellence

Data Warehousing

Wipro Technologies

2

Basic Database Architecture Differences: Oracle

Oracle SMP

DBMS Kernel

Locking Logging Multi-Task Control

Global Buffer Pools

Global Systems/Storage Area

I/O I/O I/O I/O I/O I/O I/O I/O I/O I/OI/O I/O I/O I/OI/O

DataDataPartitionPartition




3

Basic Database Architecture Differences: Teradata

Teradata MPP

BYNET Connect

PE V-Proc

Lock

Log

M-T

BPool

I/O

AMP

PE V-Proc

BYNET Connect

PE V-Proc PE V-ProcBYNET





Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP

Lock

Log

M-T

BPool

I/O

AMP





SMP Node SMP Node

Oracle SMP

4

Oracle Physical Storage

Tablespaces are individual units of storage Tablespaces have associated data files

Data files can be added to, extended or removed from a tablespace dynamically

Only partitioned objects can span tablespaces

Logical objects are stored in physical segments. Segments consist of extents Object space is allocated one extent at a time. May cause fragmentation.

5

Disk Space and the Teradata Database

DBCStores

Products

TABLE

TABLE INDEX

INDEX

BYNET Connect

PE V-Proc

LockLog

M-T

BPoolI/O

AMP

PE V-Proc

BYNET Connect

PE V-Proc PE V-ProcBYNET





LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP

LockLog

M-T

BPoolI/O

AMP





SMP Node SMP Node

6

Sample Large Disk Space Allocation DDL

Oracle9i

Teradata

drop tablespace ts_o1 including contents;create tablespace ts_o1datafile’/export/home/oracle/oracle817/dbs/datafiles/o_1’ size8190m reuseextent management localautoallocate;

.

.

.

Repeat this for every tablespace

Execute OnceCREATE USER tpcd3000g AS PERM= 5400E9, PASSWORD= tpcd3000g;

7

Comparing Database CreationDatabase Creation Task Oracle Teradata

Script(s) to CreateCatalog/Data DictionaryTables and Views

Catalog.sql, Catclust.sql,Catproc.sql

DIP

Manage “In-FlightTransactional Data

Rollback/Undo Segments Transient Journal

Database Logs Redo Logs Permanent Journal

Temporary Space/WorkSpace

Temp Space Spool Space

Default Permanent Space Default Tablespace Default Database

Table Block Size Set at Table Level for Eachbut Requires DBA Setup ofBufferpools for Each BlockSize

Set at Table Level forEachTeradata MemoryManagement forDifferent Blocksizes isAutomatic

Database Startup Information INIT.ORA and Control File XCTL, Vconfig.out

8

Create Table Statements

CREATE TABLE Table1

( Col1 NUMBER,

Col2 NUMBER,

Col3 NUMBER )

TABLESPACE Tablespace1

STORAGE (INITIAL 6144 NEXT 6144

MINEXTENTS 1 MAXEXTENTS 5 );

or...

CREATE TABLE <expl|impl column specification>AS SELECT <any query>;

Oracle

CREATE TABLE Table1 ,FALLBACK ,

NO BEFORE JOURNAL, NO AFTER JOURNAL (Col1 INTEGER, Col2 INTEGER, Col3 INTEGER)UNIQUE PRIMARY INDEX ( Col1 );

Teradata

9

Creating Tables: Similarities

All tables have names Tables have columns with data types You can define:

Constraints Referential integrity Global temporary tables Triggers

10

Creating Tables: Differences Teradata tables are created in the database

or user

Teradata provides several convenient options: Fallback Permanent journaling Table block size Primary index Built into the Table MULTISET

DBC

ProductsTABLE

11

Partitioning

Partitioning tables and indexes allow Oracle and Teradata to store lots of data With Oracle, the process of choosing partitioning methods

and partitioning keys is the balancing of query access path, performance, and data load requirements

You specifically manage the partitioning constraints and their relationship to disk storage

With Teradata, the hash partitioning algorithm is very good at evenly distributing (loading) data partitions and is the basis for high performance data access and ease of user access

Provide reasonable partitioning columns when defining the table and Teradata does the rest

Partitioning Columns are Chosen for Even Data Distribution in Both Teradata and Oracle

12

Partitioning Comparisons - Oracle

Oracle Partitioning Decisions - Decide on Methods as well as partitioning columns, set up the disk environment

99Q1

99Q4

99Q3

99Q2 Hash1

Hash4

Hash3

Hash2

Texas

California

Florida

New York

Range Partitioning Hash Partitioning

Hash1

Hash3

Hash2

Hash3

Hash2

Hash1

99Q1

99Q2

99Q3

99Q4

Composite Range PartitioningList Partitioning

13

Partitioning Comparisons-Teradata

Teradata Partitioning is a Fact of the System with Hash Data Distribution based on Primary Index (Partitioning) Columns and system managed disk

AMP2 AMP3 AMP4

Table 1 Table 1Table 1Table 2 Table 2 Table 2

AMP1

Table 1Table 2

Table 3 Table 3Table 3 Table 3

14

Examples of DDL to Create Partitioned Tables

Oracle9i Teradatacreate table orders(o_orderdate date ,o_orderkey number NOT NULL,o_custkey number NOT NULL,o_orderpriority char(15) ,o_shippriority number ,o_clerk char(15) ,o_orderstatus char(1) ,o_totalprice number ,o_comment varchar(79))pctfree 1pctused 99initrans 10storage (freelists 99 freelist groups 2)parallelnologgingpartition by range (o_orderdate)subpartition by hash(o_custkey)subpartitions 16(partition ord1 values less than (to_date(’1992-01-01’,’YYYY-MM-DD’))tablespace ts_o1...partition ord84 values less than (MAXVALUE)tablespace ts_o84);

Repeat 82 Times with DBA Defined Ranges

CREATE MULTISET TABLE ORDERTBL, DATABLOCKSIZE= 29.5 KILOBYTES(O_ ORDERKEY DECIMAL (15,0) not null,O_ CUSTKEY INTEGER not null,O_ ORDERSTATUS CHAR( 1) CASESPECIFIC not null,O_ TOTALPRICE DECIMAL( 15,2) not null,O_ ORDERDATE DATE FORMAT ’yyyy- mm- dd’ not null,O_ ORDERPRIORITY CHAR( 15) CASESPECIFIC not null,O_ CLERK CHAR( 15) CASESPECIFIC not null,O_ SHIPPRIORITY INTEGER not null,O_ COMMENT VARCHAR( 79) CASESPECIFIC not null)UNIQUE PRIMARY INDEX( O_ ORDERKEY );

15

Oracle Parallelism

Oracle parallelism is not directly related to table partitioning because of its shared disk architecture Dynamically splits data over parallel processing units for

Selects/Inserts means 1 or more parallel processing units per partition

Considers partitioning when distributing data to parallel processing units

One parallel processing unit applied to each partition for Updates/Deletes

Each user/query can get varying amounts of parallelism or run serially depending upon the resources available at query run time

May need to manually control parallelism to improve system throughput and to ensure fair distribution of parallel resources Parallel processes may funnel down to serial processing for final

sort/merge, aggregate activity

16

Teradata Parallelism

Teradata parallelism is directly related to its shared nothing architecture Automatically applied by the database Architecture ensures that each major unit of parallelism (the VAMP)

has similar amounts of data and memory Pipelining and query step parallelism is performed within the VAMP

Utility Parallelism and Query/Data Manipulation Language parallelism (Select, Insert, Update, Delete) are all the same

All system parallelism is available to ALL operations Teradata parallelism is automatic, pervasive, and database managed

All users/queries take advantage of all the system parallel resources You do not manage and control parallelism

17

Data Types

CHAR VARCHAR2 NCHAR NCHAR2 NUMBER LONG LONGRAW RAW DATE BLOB CLOB NCLOB BFILE ROWID UROWID

CHAR VARCHAR CHAR VARYING LONG VARCHAR NUMERIC DECIMAL DOUBLE PRECISION FLOAT INTEGER SMALLINT BYTEINT BYTE VARBYTE GRAPHIC VARGRAPHIC LONG VARGRAPHIC DATE REAL

Oracle Teradata

18

Oracle Teradata

Char Char

Varchar2 Varchar

Number(m,n) DECIMAL(m,n) or NUMERIC(m,n)

Date (includestime)

Date (does not include time)

Date (time portion) Time

Date Timestamp

Data Type Translations

19

In Oracle the maximum precision "m" for number is 38. In Teradata it is 19

NUMBER (without precision) has no direct counterpart in Teradata. Determine migration by contents

ROWID has no counterpart in Teradata

Datatypes

20

Constraints

Like Teradata’s Constraints - Defined on columns and tables

Oracle is different from Teradata on the follow: Default mandatory is NULL Case sensitivity is fixed at ON Constraints can be disabled and enabled

21

Oracle Specific Columns and Table

ROWNUM will number retrieved rows

ROWID indicates physical address of row

SELECT must have FROM list DUAL is a pseudo-table with 1 row

22

Creating Indexes

Similarities between Teradata and Oracle: Indexes take up space on disk Indexes can be unique and non-unique Indexes and secondary indexes provide alternate

ways to access data Differences:

Teradata indexes are not in B-tree structure Hash Subtables

Teradata automatically partitions indexes across the AMPs

Teradata uses a Primary Index for each table

23

Index Usage Comparisons

Oracle solutions traditionally have relied heavily on indexes OLTP workloads required fast access paths to few rows Decision support solutions continue Oracle’s use of

indexes where tactical queries with OLTP-like response time requirements are given more emphasis than throughput performance

Teradata solutions have traditionally not used lots of indexes

Teradata’s efficient parallel architecture emphasizes throughput performance requirements - a result of it’s DSS background

24

Index Usage Comparisons Contd. Teradata typically uses fewer indexes than the equivalent Oracle

system Saves on disk storage Reduces table maintenance windows where affected by existing

indexes Fewer database objects to manage and monitor

Most of the indexes found in Oracle may not be used on Teradata Indexes can provide clues to ad hoc query support requirements No Bit-Map indexes for Teradata Add indexes to Teradata only as workloads (or anticipated

workloads) require them Monitor their usage or lack of usage

Statistics are key - you WANT to collect statistics in Teradata!

25

Principles Behind the Use of Indexes Maximize the use of Single or Few AMP Operations:

Drive towards using single or few AMP operations for queries Minimizing the number of AMPs in an operation, all other AMPs are freed to

perform other tasks. Scalability is increased because the freed AMPs can execute more single or few

AMP operations creating greater throughput by increasing the number of tactical queries executed in parallel

Create Efficient All AMP Operations: Reduce the resource consumption on each AMP for all AMP operations. Since all AMP operations are virtually impossible to remove from a data

warehousing environment, reducing the impact on each AMP is important Gain scalability for two reasons: Individual queries execute faster freeing the AMPs to execute other queries Decrease in resource consumption allows more queries to use the shared

resources, such as spool space, or CPU

26

Miscellaneous DDL

Triggers Triggers function just the same (pre- and post-, insert /

update / delete) as in Teradata Oracle Options not in Teradata

Database Links Reference (use) objects in another instance

Synonyms Named references to objects

Sequences Number generators Often used to generate surrogate keys

HierarchiesLK

E

27

ANALYZE/Collect Statistics

ANALYZE/DBMS_STATS package are intended for collecting database object statistics for Oracle’s Cost Based Optimizer (CBO)

Goal is to collect statistics give queries good access paths Once Plans are good and stable, stop analyzing tables to

preserve plans Teradata’s Collect Statistics command collects database object

statistics Optimizer reacts to changing demographics (growing tables,

changing column value cardinality, etc.) Keeping statistics up to date ensures good plans Don’t freeze statistics - old statistics encourage old access

plans that may not be effective as the database changes

28

Data Control Language

Data Control Language (DCL) is used in both Oracle and Teradata to assign user access

Oracle users may be granted: Object Privileges

Easily relate to Teradata System Privileges

Can be simulated within Teradata

29

User Access Rights

Teradata enables you to assign access rights: To individual users To logical groups of users On individual objects On groups of objects

ViewsViews

MacrosMacros

TablesTables

30

Object Privileges

Grant Execute Procedure/Grant Execute

Grant Execute

Grant UpdateGrant Update

Grant InsertGrant Insert

Grant SelectGrant Select

Grant Index orGrant Drop Table

Grant Index

Grant DeleteGrant Delete

Grant DropGrant Alter

Granting Teradata Privileges

Granting Oracle Privileges

31

System Privileges

Grant Drop View or Grant View on Database

Grant Drop Any View

Grant Create View or Grant View on Database

Grant Create Any View

Grant Create View or Grant View on Database

Grant Create View

Grant Select on DatabaseGrant Select Any Table

Grant Update on Database/Grant Update (column list, all but column list)

Grant Update Any Table

Grant Insert on Database Grant Insert Any Table

Grant Drop Table or Grant Table Grant Drop Any Table

Grant Delete on Database Grant Delete On Any Table

Grant Create Table or Grant Table Grant Alter Any Table

Grant Create Table or Grant Table Grant Create Table

Granting Teradata PrivilegesGranting Oracle Privileges

32

Questions ?

teradata oracle comparision

Documents

Transcript of teradata oracle comparision