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JFS parameters for ORACLE

George Nikoloudis_1
Frequent Advisor

JFS parameters for ORACLE

Dear all

What is better to have a large or a small JFS fragmented block size between 1,2,4,8 KB?

When the FS block is 8KB and the fragment block is 2KB is the JFS performs 4 IO operations in order to fill up the 8KB block?

My DB has 8KB db_block size.
harry d brown jr
Honored Contributor

Re: JFS parameters for ORACLE

Block Size and File Size Although data storage space is often measured in megabytes (one MB = 1024 * 1024 bytes), the HP-UX operating system and Oracle7 Server each perform input and output in units of data storage called blocks. The size of the operating system blocks is not necessarily equal to Oracle blocks.

Oracle7 Server block size is not fixed. You can set its value when creating a database by changing the DB_BLOCK_SIZE parameter in the initsid.ora file.

Changing the Oracle block size can change Oracle performance, depending on the disk hardware, file system, and application. Experiment with different block sizes to see what is most efficient for your configuration. The default size 2 KB should be adequate for most circumstances, but some performance benefits can be gained by modifying the Oracle block size on your system.


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Vincent Farrugia
Honored Contributor

Re: JFS parameters for ORACLE


Follow this thread:


especially Jared Westgate's answer.

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