DBAsupport.com Forums - Powered by vBulletin
Results 1 to 3 of 3

Thread: Buffer cache low hit rate and table scans...

  1. #1
    Join Date
    Sep 2000
    Posts
    78

    Wink

    Hi,

    I have a table that has about 200,000 rows. Most of the queries do full table scan since they retreive large portion of this table. On every table scan I get very low (sometimes even 0%) buffer cache hitratio. I set the table with the CACHE parameter to cache the retrieve rows, but it still has low cache hit ratio.

    How do i increase teh hit ratio? shoul I increase the buffer cache (for now it is 78 MB) and my total RAM is392 MB..

    What should I do?

    Thanx!

  2. #2
    Join Date
    Aug 2000
    Location
    Belgium
    Posts
    342
    I think the 'cache'd table is consuming lots of space in you buffer cache, leaving to little space for other data, resulting in a low hit ratio.

    Hope this helps
    Gert

  3. #3
    Join Date
    Nov 1999
    Location
    Elbert, Colorado, USA
    Posts
    81
    If you are using Oracle8 or 8i, you might consider splitting your buffer cache into KEEP, RECYCLE, and DEFAULT pools. You can then specify your table should be loaded in the KEEP pool and (assuming everything is sized properly) it won't be aged out as quickly.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  


Click Here to Expand Forum to Full Width