Databse & Technology 2 _ Shan Nawaz _ Oracle 11g Top 10 features - not your usual Top 10.pdf

The most comprehensive Oracle applications & technology content under one roof The most comprehensive Oracle applications & technology content under one roof

Oracle11g Top 10 features Not your usual Top 10.

Shan Nawaz Verisign Inc

The most comprehensive Oracle applications & technology content under one roof

WHO AM I •  Shan Nawaz

–  More than 13 years of experience in Database Technologies(Oracle, DB2, SQL Server)

•  Database Engineer at Verisign –  Tune mission criJcal applicaJons with millisecond SLA’s

•  Industry CerJficaJons –  OCP in Oracle7.3/8/9i/10g/11g –  IBM CerJfied User specialist in DB2 –  MCP in SQL Server 2000

•  Recent/Future Technical Sessions –  Oracle Open World 2011 –  Hotsos 2011 –  IOUG 2011 –  Oracle Open World 2010 –  Verisign Technical Symposium 2009


Agenda

•  About Verisign and Our SLA’s •  Not your usual Top 10 features •  QA •  References


Our SLA’s

•  TransacJons made of complex SQL statements

Command SLA

CHECK DOMAIN 25ms

ADD DOMAIN 50ms

DELETE DOMAIN 100ms

MODIFY DOMAIN 100ms


Goal/MoJvaJon of this PresentaJon

•  To visit Australia

•  To talk about the very good features of Oracle11g that are overlooked by the very best features of Oracle 11g


Very Best Features 1.   Database Replay 2.   AdapGve Cursor Sharing 3.   Flashback Data Archive/Total Recall 4.   EdiGon Based redefiniGon 5.   Deferred segment creaGon 6.   Password Enhancements 7.   SQL Plan Management 8.   Result Cache 9.   Virtual Indexes/Columns 10.   Interval/System ParGGoning 11.   Extended OpGmizer StaGsGcs 12.   Online Patching 13.   Recursive With clause 14.   PL/SQL NaGve CompilaGon 15.   Secure Files


Poor man’s parallelism


Poor man’s parallelism DBMS_PARALLEL_EXECUTE

•  Supports parallel update of large data sets in smaller chunks.

•  Chunks are created by segregaJng the data based on 1.  Rowid 2.  Numeric column 3.  User-‐defined SQL.



•  Why is DBMS_PARALLEL_EXECUTE important ? – Unlike other parallel features , DBMS_PARALLEL_EXECUTE does not require Enterprise EdiJon.

– Eliminates much of manual coding and does befer job of distribuJng load uniformly across parallel processes

– Overcome restricJons of parallel DML


Poor man’s parallelism •  Why is DBMS_PARALLEL_EXECUTE important ? (ConJnued) –  Break large single transacJon into mulJple chunks (transacJons) •  Less impact to dependent systems like Golden Gate or streams

•  Less undo space required minimizing the chance of ORA-‐1555

•  DuraJon of lock is reduced. –  Restart failed chunks (transacJons) since Chunks are commifed individually (Implicit) •  Impact of Rollback due to error is not severe.


Poor man’s parallelism DBMS_PARALLEL_EXECUTE

•  How to implement? 1.  Create a task with CREATE_TASK procedure 2.  Create chunks (size) using one of the following.

–  CREATE_CHUNKS_BY_ROWID –  CREATE_CHUNKS_BY_NUMBER_COL –  CREATE_CHUNKS_BY_SQL

3.  Define the DML statement 4.  Execute the task in parallel with RUN_TASK 5.  Perform error handling and run failed chunks with

RESUME_TASK.



Create a task with CREATE_TASK BEGIN DBMS_PARALLEL_EXECUTE.CREATE_TASK (TASK_NAME => 'UPDATE_TASK'); END;

Create chunks with ROWID. BEGIN DBMS_PARALLEL_EXECUTE.CREATE_CHUNKS_BY_ROWID(TASK_NAME => 'UPDATE_TASK‘, TABLE_OWNER

=> 'SCOTT‘, TABLE_NAME => 'CONTENT‘, BY_ROW=> FALSE, CHUNK_SIZE => 3075); END;

Define the Update statement and running the task DECLARE L_SQL_STMT VARCHAR2(32767); BEGIN L_SQL_STMT := 'UPDATE /*+ ROWID (DDA) */ CONTENT SET EXPIRATION_DATE= SYSDATE+14 WHERE ROWID BETWEEN :START_ID AND :END_ID'; DBMS_PARALLEL_EXECUTE.RUN_TASK(TASK_NAME => 'UPDATE_TASK‘,SQL_STMT=> L_SQL_STMT,LANGUAGE_FLAG

=> DBMS_SQL.NATIVE,PARALLEL_LEVEL=> 4); END;


Compare and Converge


Compare and Converge DBMS_COMPARISON

•  IdenJfy differences between data sets across databases or same database.

•  Report and Synchronize the data set –  Either the source or target can act as master.

•  Intended mainly for replicated/streams environment but can be used outside of streams environment

•  Works with 10g and above version provided one the databases in the comparison is 11g;



•  Comparison Modes Supported 1.  Full Object comparison

•  CMP_SCAN_MODE_FULL 2.  Random data comparison

•  CMP_SCAN_MODE_RANDOM 3.  Cyclic Comparison

•  CMP_SCAN_MODE_CYCLIC 4.  Customized comparison

•  CMP_SCAN_MODE_CUSTOM



•  Objects currently supported are –  Tables –  Single Table Views – Materialize Views –  Synonyms for above objects

•  Unique Indexes are used for comparison – Non-‐Unique indexes are used if specified manually

•  Permits comparing row-‐row OR group of rows –  Befer performance with group of rows



•  Steps 1.  Create comparison object 2.  Perform the comparison 3.  Analyze the results 4.  Converge the data


Compare and Converge SQL> SELECT COUNT(*) FROM

CONTENT_1; COUNT(*) -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ 10

SQL> SELECT COUNT(*) FROM CONTENT_2;

COUNT(*) -‐-‐-‐-‐-‐-‐-‐-‐-‐-‐ 10 SQL> DELETE FROM CONTENT_2 2 WHERE ITEM_ID=484380; 1 row deleted. SQL> COMMIT;



Create Comparison Object SQL> BEGIN 2 DBMS_COMPARISON.CREATE_COMPARISON( 3 COMPARISON_NAME=>'MYCOMPARE', 4 SCHEMA_NAME=>'SCOTT', 5 OBJECT_NAME=>'CONTENT_1', 6 DBLINK_NAME=>NULL, 7 REMOTE_SCHEMA_NAME=>'SCOTT', 8 REMOTE_OBJECT_NAME=>'CONTENT_2'); 9 END; 10 / PL/SQL procedure successfully completed.

SQL> DECLARE 2 COMPARE_VALUE

DBMS_COMPARISON.COMPARISON_TYPE; 3 COMPARE_OUTPUT BOOLEAN; 4 BEGIN 5 COMPARE_OUTPUT := 6 DBMS_COMPARISON.COMPARE ( 7 COMPARISON_NAME=>'MYCOMPARE', 8 SCAN_INFO=>COMPARE_VALUE, 9 PERFORM_ROW_DIF=>TRUE); 10 IF COMPARE_OUTPUT=TRUE 11 THEN 12 DBMS_OUTPUT.PUT_LINE('Tables are IdenGcal'); 13 ELSE 14 DBMS_OUTPUT.PUT_LINE('Tables are not IdenGcal’); 15 END IF; 16* END; 17 / Tables are not IdenJcal, Differences Exist PL/SQL procedure successfully completed.


Reproducing SQL Test Case


Reproducing SQL Test Cases

•  Remember the Jmes you were unable to resolve SQL issue

•  Because –  You are unable to reproduce the issue at will in producJon environment.

– Or Unable to reproduce the issue easily in Dev/QA environments. (Recurring issue)

– Or Oracle support was unable to help you because they don’t have the necessary informaJon to reproduce the issue


Reproducing SQL Test Cases •  Help is on the way •  Oracle 11g provides a tool called SQL Test case builder or SQL TCB. –  As per Oracle documentaJon, If you ever need to contact Oracle Support about a SQL issue, then obtaining a reproducible test case is the single most important factor to ensure a speedy resoluJon.

•  Provides as means of good shared language for exchanging informaJon with Oracle Support or DBA’s or developers. – Easy to diagnose , analyze and esJmate the fix.

•  Back ported to 10.2.0.4



•  Test case can be generated using 1.  SQL text 2.  SQL cursor 3.  SQL from incident file

•  SQL TCB can be also be directly with ADRCI command – DDE EXECUTE ACTION INCIDENT <incident_id> ACTIONNAME SQLTCB INVOCATION <invocaJon_id>


Reproducing SQL Test Cases •  What kind of data is collected?

Permanent InformaGon •  Always captured •  InformaJon like SQL_TEXT,

disk reads, buffer gets, CPU Jme, elapsed Jme, fetches, ExecuJon plan , OpJmizer staJsJcs, Bind variables, rows processed Use of Outlines, SQL profiles or SPM and metadata and user profile.

•  Data collecJon is opJonal •  No Support for DDL

Transient InformaGon •  Captured if Oracle thinks it is

necessary •  InformaJon that could

necessarily change like dynamic sampling, degree of parallelism



•  How to implement STB? 1.  Create a directory or use exisJng directory 2.  Export the test case with

DBMS_SQLDIAG.EXPORT_SQL_TESTCASE 3.  Import the test case with

DBMS_SQLDIAG.IMPORT_SQL_TESTCASE


Reproduce SQL Test Cases

•  Example

SQL> DECLARE 2 MYTESTCASE CLOB; 3 BEGIN 4 DBMS_SQLDIAG.EXPORT_SQL_TESTCASE ( 5 DIRECTORY=>'DATADIR', 6 SQL_TEXT=>'SELECT DOMAINNAME FROM DOMAIN

WHERE DOMAINNAME=2703255', 7 EXPORTDATA=> FALSE, 8 TESTCASE_NAME=>'MYTEST', 9 TESTCASE=>MYTESTCASE); 10 END; 11 /


SQL Test Case Builder

•  Dump directory files created by SQL TCB.


Advanced Compression


ADVANCED COMPRESSION

•  With huge amounts of data being the norm than excepJon , compression becomes criJcal in reducing the foot print of almost every component

Database

Network

Backup Server

Buffer Cache



In 11g, there is compression for everyone •  Storage – OLTP compression for DML (Structured Data) –  SecureFiles Compression (Unstructured Data)

•  Network – Data Guard redo Compression

•  Backup –  RMAN compression – Data pump compression


ADVANCED COMPRESSION OLTP Compression

•  New compression algorithm uses deferred

or batched approach –  Data is inserted as is without compression unJl PCTFREE value is reached.

–  Compression of data starts once PCTFREE threshold is reached •  Can be enabled at table, parJJon or tablespace level •  No need of decompressing the data while reading •  Recommended for low update acJvity tables •  Use Compression advisor(DBMS_COMPRESSION) to

esJmate savings

DATA

PCTFREE


ADVANCED COMPRESSION Data guard Compression

•  Redo is compressed as it is transmifed over a network.

•  Helps efficiently uJlize network bandwidth when data guard is across data centers

•  Faster resynchronizaJon of Data guard during gap resoluJon.

•  Recommended for low network bandwidth



Data guard Compression

•  How to implement? – Specify “COMPRESSION” with iniJalizaJon parameter LOG_ARCHIVE_DEST_n



RMAN Compression

•  Supports compression of backups using ZLIB algorithm – Faster compression and low CPU uJlizaJon compared to default BZIP2 (10g)

– Low compression raJo compared to BZIP2



RMAN Compression •  How to Implement ? – Configured with CONFIGURE COMPRESSION ALGORITHM ‘value’ • With Advanced compression , value can be HIGH, MEDIUM(ZLIP) and LOW(LZO) • Without advanced compression , Only basic can be specified

– Execute backups with ‘AS COMPRESSED BACKUPSET’



Data Pump Compression

•  Compression of metadata introduced in 10g •  Compression of data introduced in 11g. •  Inline operaJon – Save on storage allocaJon – No need to uncompress before Import



Data Pump Compression

•  How to implement? – Enabled with expdp COMPRESSION afribute

•  ALL •  DATA_ONLY •  METADATA_ONLY


Diagnosing and resolving failures


Diagnosing and Resolving Failures •  Database Recovery advisor (DRA) – Diagnosing media Failures –  Present repair opJons (with script) –  Repair failures (if requested)

•  Doesn’t mafer if you are a newbie DBA or highly experienced DBA – When in doubt , use DRA.

•  Now you can blame Oracle if the something goes wrong. – And keep your Job, write a blog ……


Diagnosing and Resolving Failures

•  The three RMAN commands to support DRA 1.  LIST FAILURE

•  Errors are classified as Low, High, CriJcal •  Historical support for closed errors.

2.  ADVISE FAILURE •  Specifies the repair strategy •  Supports both manual and automated repair opJons

3.  REPAIR FAILURE •  Supports preview mode (spooling the script)


MulGsecGon Backups


MulJsecJon Backups

•  Enables backing up of single datafile in parallel using secJons – SecJon is conJguous range of blocks in a datafile

•  Up to 256 SecJons or channels per datafile is supported

•  MulJplexed backups will not contain datafiles or secJons from other datafiles.


MulJsecJon Backups

•  Benefits –  Improved performance for backup and restore.

•  Befer performance when restoring one datafile compared to restoring from large mulJplexed backup set

– Befer restartability. •  Restart the failed secJon backup instead of datafile


MulJsecJon Backups


MulJsecJon Backups


MulJsecJon Backups


DATABASE RESIDENT CONNECTION POOL



•  Shared Server or MTS –  Session Resources are not shared – Good for long running transacJons

•  Database resident connecJon pool(DRCP) –  To support large number of similar client applicaJons or connecJons

–  Share or reuse sessions. –  TransacJons are very short in nature – No Session affinity is required



•  DRCP is mainly intended for single threaded applicaJons like PHP , PERL –  Currently available to clients that use the OCI driver with C, C++, Perl and PHP.

–  No support for JDBC thin or JDBC-‐OCI. •  More database connecJons are supported compared to

shared server or dedicated server configuraJon –  Less memory foot print –  Behaves more like dedicated server connecJon once the connecJon is established.


Database Resident ConnecGon Pool

•  Working of DRCP 1.  Client makes a request for connecJon 2.  Background process connecJon broker picks up

appropriate pooled server and hands-‐off the client to that pooled server.

3.  Once connecJon is handed-‐off, the client directly communicates with the pooled server

4.  The pooled server is handed back to the broker when the client releases it.



•  Working of DRCP

PGA POOLED SERVERS

Clients/Middle Ger

ConnecGon Broker



•  How to configure? –  Start the pool with DBMS_CONNECTION_POOL.START_POOL();

– Add (SERVER = POOLED) to TNS entry –  You can also use the following syntax for PHP

•  oci_pconnect(“userid", “pwd", “hostname:1526/orcl:POOLED"); –  Pool can be stopped with DBMS_CONNECTION_POOL.STOP_POOL();

–  Pool properJes like minimum and maximum number of pooled servers , maximum inacJvity Jme etc. can be specified with DBMS_CONNECTION_POOL . CONFIGURE_POOL package


Server ConsolidaGon


Server ConsolidaJon •  Very simple and effecJve approach to Server ConsolidaJon

•  Limit the CPU used by an Instance – Works by limiJng the number of runnable processes

•  Administered and maintained by DBA instead of SA’s

•  Supports over-‐provisioning •  Will not help with licensing if your server has more CPU’s (At least for now, please check with Oracle)


Server ConsolidaJon

•  How to enable instance caging? – Enable the Resource Manager.

•  ALTER SYSTEM SET RESOURCE_MANAGER_PLAN = ‘DEFAULT_PLAN;

– Set the CPU_COUNT iniJalizaJon parameter. •  ALTER SYSTEM SET CPU_COUNT = 2;


Server ConsolidaJon

•  What is the secret formula? – CPU_COUNT/Total number of acJve instances

•  Example: 8 CPU server with 4 instances – Each instance is limited to 2 CPU(CPU_COUNT) – CASE-‐1: If all 4 instances are acJve

•  Each instance gets 2/(4*2) =25% of Total CPU – CASE-‐2: If 2 instances are acJve

•  Each instance gets 2/(2*2) = 50% of Total CPU


SQL*Plus Error Logging


SQL*Plus Error Logging •  Records SQL, PL/SQL and SQL*Plus errors in an error table – Default table is SPERRORLOG; –  Created automaJcally if the table does not exists

•  Captures errors that are not SQL too. –  SELCT instead of SELECT

•  This is SQL*Plus feature and works with older versions of Oracle database – Only the clients must be 11g or above

•  Is it Jme to say bye bye to spooling, Wait not yet



•  All you have to do is type “SET ERRORLOGGING ON”

•  Allows you to idenJfy the session with idenJfier –  SET ERRORLOGGING ON IDENTIFIER ‘Core-‐Release 2.3’

•  Allows use of user-‐defined table •  SET ERRORLOGGING ON TABLE scof.errorlog

•  Allows truncaJng of tables before capturing errors –  SET ERRORLOGGING ON TRUNCATE




Preprocessor


Oracle Preprocessor

•  Provides the ability to preprocess your data before sending to Oracle external drivers – Reduced disk space consumpJon and faster processing Jme.

– Adds befer control and flexibility to external tables


Oracle Preprocessor

•  Supports OS commands, binaries and scripts •  Supports parallelism –  File is granular unit for parallelism.

•  Back ported to 10.2.0.5 •  Other uses –  For SQL lovers , run vmstat , df –k or sar report from SQL prompt.

•  CauJon –  Restrict access to preprocessor directory


Oracle Preprocessor


References

•  Oracle DocumentaJon •  Oracle Metalink •  asktom.oracle.com •  OTN ArJcles •  hfp://opJmizermagic.blogspot.com •  hfp://kkempf.wordpress.com •  hfp://php.net/manual/en/oci8.connecJon.php •  And many more …..

Documents

Databse & Technology 2 _ Shan Nawaz _ Oracle 11g Top 10 features - not your usual Top 10.pdf