Saturday, November 06, 2010

Improve Import/ Export performance


Set the BUFFER parameter to a high value (e.g. 2M)
Set the RECORDLENGTH parameter to a high value (e.g. 64K)
Stop unnecessary applications to free-up resources for your job.
If you run multiple export sessions, ensure they write to different physical disks.
DO NOT export to an NFS mounted filesystem. It will take forever.


Create an indexfile so that you can create indexes AFTER you have imported data. Do this by setting INDEXFILE to a filename and then import. No data will be imported but a file containing index definitions will be created. You must edit this file afterwards and supply the passwords for the schemas on all CONNECT statements.
Place the file to be imported on a separate physical disk from the oracle data files
Increase DB_CACHE_SIZE (DB_BLOCK_BUFFERS prior to 9i) considerably in the init$SID.ora file
Set the LOG_BUFFER to a big value and restart oracle.
Stop redo log archiving if it is running (ALTER DATABASE NOARCHIVELOG;)
Create a BIG tablespace with a BIG rollback segment inside. Set all other rollback segments offline (except the SYSTEM rollback segment of course). The rollback segment must be as big as your biggest table (I think?)
Use COMMIT=N in the import parameter file if you can afford it
Use ANALYZE=N in the import parameter file to avoid time consuming ANALYZE statements
Remember to run the indexfile previously created

Sukhwinder singh


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