Data Guard New Features

11g Data Guard New Features -- Fan Xiangrong

Agenda Common changes

Password file Redo compress shipping

Physical standby changes Active standby Snapshot database Corrupted block automatic replacement RMAN duplicate standby from active database

Logical standby changes Online modify logical standby parameters Compressed table is supported by logical standby SQL Apply will execute parallel DDLs in parallel

Agenda Common changes

Password file Redo compress shipping

Physical standby changes Active standby Snapshot database Corrupted block automatic replacement Use RMAN to build physical standby

Logical standby changes Dynamic parameters change Compressed table is supported by logical standby SQL Apply will execute parallel DDLs in parallel

Password file

Create password file on standby doesnrsquot work You need to copy password file from primary to standby

Redo Compress Shipping Add ldquocompression=enablerdquo to log_archive_dest_N

parameter log_archive_dest_3 = service=(DESCRIPTION=

(ADDRESS=(PROTOCOL=TCP)(HOST=qadb27qaebaycom)(PORT=1799))(CONNECT_DATA=(SID=TEST2))) compression=enable reopen=5 lgwr async

For 11g R1 it only uses compression when resolving gaps If you set hidden parameter _REDO_TRANSPORT_COMPRESS_ALL=TRUE it will use compression for all redo transport

Redo Compress TestSQL to generate redo

create table test tablespace data01 as select from dba_objectsbegin for i in 18 loop insert into test select from test commit end loopend

Check ldquobytes received via SQLNet from clientrdquo statistics on standby

1st testCompression = enable 594M- 507M = 87MCompression = disable 959M- 595M = 364M

2st TestCompression = enable 1046M-959M = 87MCompression = disable 1410M-1047M=363M

Compression rate is 24 Different data can have different compress rate

It needs License

Redo transport compression is a feature of the Oracle Advanced Compression option You must purchase a license for this option before using the redo transport compression feature

Agenda Common changes

Password file Redo compress shipping

Physical standby changes Active standby Snapshot database Corrupted block automatic replacement RMAN duplicate standby from active database

Logical standby changes Dynamic parameters change Compressed table is supported by logical standby SQL Apply will execute parallel DDLs in parallel

Active Standby

Simple Steps

bullSQLgt RECOVER MANAGED STANDBY DATABASE CANCEL104867310486731048673

Stop redo applybullSQLgt

ALTER DATABASE OPEN READ ONLY

Open the database read

only

bullSQLgt RECOVER MANAGED STANDBY DATABASE DISCONNECT USING CURRENT LOGFILE

Restart redo apply

Disallow operations

Any DML (insert update delete) Any DDL Access of local sequences DMLs on local temporary tables

Check Standby Apply Status V$databasecurrent_scn records the current apply SCN

SQLgt select scn_to_timestamp(current_scn) from v$database

SCN_TO_TIMESTAMP(CURRENT_SCN)---------------------------------------------------------------------------21-NOV-09 084243000000000 AM

Session level parameter STANDBY_MAX_DATA_DELAY(11g R2)

The new STANDBY_MAX_DATA_DELAY session parameter can be used to specify a session-specific apply lag tolerance measured in seconds for queries issued by non-administrative users to a physical standby database that is in real-time query mode

Alter session set STANDBY_MAX_DATA_DELAY = integer | NONE

Snapshot database A snapshot standby database is a fully update-able standby

database that is created by converting a physical standby database into a snapshot standby database

Snapshot standby database receives and archives but does not apply the redo data

Redo data received from the primary database is applied automatically once it is converted back into a physical standby database

All local updates will be discarded when snapshot database is converted back to physical standby database

In 10g version we can do it manually

10g Manual Steps

httpdbmonitorvipqaebaycomdbblogmainphpname=Sub20doc200911222010g20put20standby20in20read-write20using20flashbackhtm

Convert to Snapshot database Steps

If not already configured configure flash recovery area as given below

Set the size for recovery area Alter system set db_recovery_file_dest_size=ltsizegt

Set Flash recovery area (unset db_recovery_file_dest and set db_recovery_file_dest_1)Alter system set db_recovery_file_dest=ltpathgt

Bring the physical standby database to mount stage

Stop managed recovery if it is active

Convert to snapshot standby database

ALTER DATABASE CONVERT TO SNAPSHOT STANDBY

Shutdown and startup

Convert back to Physical Standby Steps

Shutdown the snapshot standby database Bring the database to the mount stage Issue the command

ALTER DATABASE CONVERT TO PHYSICAL STANDBY

Shutdown the database and mount it Start the media recovery process

Corrupted block replacement

A corrupted data block in a primary database can be automatically replaced with an uncorrupted copy of that block from a physical standby database that is operating in real-time query mode

A corrupted block in a physical standby database can also be automatically replaced with an uncorrupted copy of the block from the primary database if LOG_ARCHIVE_CONFIG LOG_ARCHIVE_DEST_n parameters are set on standby

RMAN Duplicate Standby

RMAN Duplicate Standby

Prepare standby system Setup listener Create an initora file with only db_name in it Create or copy a password file Startup nomount database Create spfile from pfile

Prepare primary system Create spfile from pfile

RMAN build scriptrman target syssystest_pri AUXILIARY syssystest_targetrun allocate channel prmy1 type diskallocate auxiliary channel stby1 type diskduplicate target database for standby from active databasespfileparameter_value_convert GBPGWDDSset db_unique_name=TESTset control_files=oracleDDSarchiveTESTcontrolctlset log_archive_dest_1=location=oracleDDSarchiveTESTarchiveset db_file_name_convert=oracleGBPGWdata01TESToracleDDSarchiveTESTsetlog_file_name_convert=oracleGBPGWdata01TESTredooracleDDSarchiveTEST

redolsquoset log_archive_dest_3=lsquorsquonofilenamecheck

Agenda Common changes

Password file Redo compress shipping

Physical standby changes Active standby Snapshot database Corrupted block automatic replacement Use RMAN to build physical standby

Logical standby changes Dynamic parameters change Compressed table is supported by logical standby SQL Apply will execute parallel DDLs in parallel

Dynamic parameters change

select from dba_logstdby_parametersSQLgt

NAME VALUE UNIT SETTING DYNAMIC------------------------------ -------------------- ---------- ---------- ----------MAX_SGA 30 MEGABYTE SYSTEM YESMAX_SERVERS 9 SYSTEM YESPREPARE_SERVERS 1 SYSTEM YESAPPLY_SERVERS 5 SYSTEM YESMAX_EVENTS_RECORDED 10000 SYSTEM YESRECORD_SKIP_ERRORS TRUE SYSTEM YESRECORD_SKIP_DDL TRUE SYSTEM YESRECORD_APPLIED_DDL FALSE SYSTEM YESRECORD_UNSUPPORTED_OPERATIONS FALSE SYSTEM YESEVENT_LOG_DEST DEST_EVENTS_TABLE SYSTEM YESLOG_AUTO_DELETE TRUE SYSTEM YESLOG_AUTO_DEL_RETENTION_TARGET 1440 MINUTE SYSTEM YESPRESERVE_COMMIT_ORDER TRUE SYSTEM NO_EAGER_SIZE 1000 USER YES

Compressed table is supported (112)

DSS table compression Create table hellip compress as selecthellip

OLTP table compression Alter table hellip compress for all operations

Parallel DDL is supportedPrimary

SQLgt create index test1 on test(object_name) tablespace data01 parallel 4

Index created

Target

583 oracleqadb27 (P002) log buffer space 000 0 0 00 A 14 13 575 oracleqadb27 (P003) log buffer space 000 0 0 00 A 14 13 595 oracleqadb27 (P000) direct path read temp 10319291 3 0 00 A 14 14 601 oracleqadb27 (P001) direct path read temp 103147291 -1 0 00 A 14 13 576 oracleqadb27 (P004) PX Deq Execution Msg 26856652720 0 1 00 I 1 13 665 oracleqadb27 (P006) PX Deq Execution Msg 26856652720 0 1 00 I 2 13 574 oracleqadb27 (P005) PX Deq Execution Msg 26856652710 0 1 00 I 1 13 647 oracleqadb27 (P007) PX Deq Execution Msg 26856652710 0 1 00 I 1 13

Others

Statspack on standby (4548481) Support different platforms (4134841) Big performance boost in Oracle 11G Up to

100 increase in redo apply performance

Review Common changes

Password file Redo compress shipping

(_REDO_TRANSPORT_COMPRESS_ALL=TRUE for 11gR1) Physical standby changes

Active standby Snapshot database Corrupted block automatic replacement RMAN duplicate standby from active database

Logical standby changes Online modify logical standby parameters Compressed table is supported by logical standby (11g R2) SQL Apply will execute parallel DDLs in parallel