oracle parameter

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SAP Note 936441 - Oracle settings for R3load based systemcopy

Note Language: English Version: 12 Validity: Valid Since 13.01.2009

Summary

SymptomUnicode migrations, heterogenous system copies or platform migrations taketoo long

Other termsUnicode migration, platform migration, R3load, R3szchk

Reason and PrerequisitesOracle 9.2.x, Oracle 10.2.x, 64bit Operating Systems

SolutionMigrations based on R3load generate a specific workload on the Oracledatabase which is quite different from a typical production databaseworkload of a R/3 or BW system.

Therefore a different Oracle configuration and parametrization is requiredto achieve optimal database throughput during the export and import phaseof the R3load process reducing the total migration time.

After the migration has been completed the database and parametrizationshould be changed back to the recommended production settings of the Oracledatabase for R/3 and BW.

The following list contains the necessary steps to achieve the bestdatabase throughput during a system copy with R3load:

1. Use loadprocedure fast option of R3load (Details in OSSnote 1045847)

2. Create Oracle Data Dictionary statistics for sourcedatabase (Only relevant for Oracle 9.2.x systems. Details inOSS note 558746)This will reduce substantially the runtime of the R3szchk utility.WARNING: In a R/3 system you must remove the statistics explained in note 558746 after the R3szchk has run successfully !!!

3. Database parametrization (init.ora/spfile)The following settings are designed for 64bit operating systems withoutprocess address space limitations.Furthermore it is assumed that the Oracle database runs on a dedicatedserver and that the R3Load processes will be running on one or moredifferent servers.If not otherwise noted the settings are valid for both the source databaseas well as the target database.

o pga_aggregate_target = 70% of main memory size (for targetdatabase)

o pga_aggregate_target = 40% of main memory (for sourcedatabase with all tables being exported in sorted order)

o _pga_max_size = 2147483648 (2GB)

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o db_cache_size................= 20% of main memory size (for targetdatabase)

o db_cache_size = 50% of main memory size (for sourcedatabase)

o db_file_multiblock_read_count = 128 (only for Oracle9.2)

o filesystemio_options = setall

o disk_asynch_io = true

o db_writer_processes = 20 (onlyfor platforms which do not support async_io and direct_io. CheckOSS notes 999524 and 834343 for which platforms support async_ioand direct_io. If a platform supports async_io and direct_io, thenthe parameter should not be set.)

o log_buffer = 10485760 (10MB)(should be 1MB if platform supports async_io and direct_io, checkOSS note 999524 and 834343)

o parallel_execution_message_size = 16384

o parallel_threads_per_cpu = 1

o parallel_max_servers =number of CPUs * number of concurrent R3Load processes * 2

o processes = processes + parallel_max_servers

4. Database configuration

o Size of PSAPTEMP tablespace in source and target database should beat least 20% of used data. Amount ofused data can be checked by queryingselect (sum) bytes from dba_segments;

o Put redo log files on raw devices if OS and filesystem do notsupport async, direct and concurrent IO (see also OSS note 834343or 999524)

The following changes are designed to reduce unnecessary disk I/O

o Disable archiving in database(alter database noarchivelog)

o Disable redo log mirroring, use only one redo log member per redogroup.

5. Network configurationThe following changes are designed to optimize network traffic betweendatabase server and the server(s) running the R3Load processes

o Use Gigabit Ethernet

o Use hardware vendor specific techniques (such as Ether Channeling)

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to multiplex network traffic across more than one networkconnection

o Configure Jumbo Frames

o Use dedicated private network segments

o SQL*Net configuration:

- Increase SDU_SIZE in listener.ora to 32KB

- Increase SDU_SIZE in tnsnames.ora to 32KB

- Specify tcp.nodelay=yes in sqlnet.ora

6. DDLORA.TPL changesThe utility R3ldctl will add PARALLEL, NOLOGGING and COMPUTE STATISTICSclauses to create primary key (crepky) and create index (creind) sectionsin DDLORA.TPL template files. To use this new functionality you need to useat least the following R3ldctl versions:

o R3ldctl 6.40, Patch Level 1

o R3ldctl 7.00, Patch Level 1

Header Data

Release Status: Released for CustomerReleased on: 19.01.2009 10:15:18Master Language: EnglishPriority: Recommendations/additional infoCategory: PerformancePrimary Component: BC-DB-ORA Oracle

The Note is release-independent

Related Notes

Number Short Text

1319517 Unicode Collection Note

1045847 ORACLE DIRECT PATH LOAD SUPPORT IN R3LOAD

1043380 Efficient Table Splitting for Oracle Databases

999524 Oracle 10.2 platform support for Async IO

971646 6.40 Patch Collection Hom./Het.System Copy ABAP

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Number Short Text

970518 Hom./Het.System Copy SAP NetWeaver 7.0 (2004s) SR2

940561 ORACLE DIRECT PATH LOAD DOES NOT LOAD PARALLEL SINGLE TABLE

926085 (OUTDATED) Hom./Het.System Copy SAP NetWeaver 7.0 SR1

870863 (OUTDATED) Hom./Het.System Copy SAP NetWeaver 2004s

857081 Unicode conversion: downtime estimate

834343 Oracle 9.2 Platform Support for Async IO

806554 FAQ: I/O-intensive database operations

784931 Hom./Het.System Copy SAP Web AS 6.40 SR1 ABAP

765475 Unicode Conversion: Troubleshooting

632556 Oracle 9.2.0.* database parameterization for BW

575280 Add info about upgrade to SAP Web AS 6.20 ORACLE 9.2.0

558746 Better Oracle Data Dictionary BW Performance

554031 Creating space statistics with BRCONNECT

548016 Conversion to Unicode

124361 Oracle parameterization (R/3 >= 4.x, Oracle 8.x/9.x)

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