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Home -> Community -> Usenet -> c.d.o.server -> Re: Cache hit rate
On Mon, 18 May 1998 15:59:44 GMT, larionov_at_yahoo.com <larionov_at_yahoo.com> wrote:
>Sorry if this question(s) sounds silly!
>
>I want to improve the cache hit rate.
>Would it help If I decrease multiblock_read_count?
>
>On my system I have a bunch of random updates,
>where just one row is search-updated in a 5GB table.
>Of ourse I don't need to read 32 blocks to update
>just one row, so high multiblock_read_count is just a waste of
>SGA! Am I wrong?
This multiblock is for full table scans, so there is no effect on random updates (unless you don't have any indices, in which case you have worse problems... :)
Since you probably have some other tables that do get scanned, your cache hit rate would probably decrease by decreasing the count.
>
>Also, can I set the multiblock_read_count just for one table
>and leave untouched for other tables?
Only if it is the only table in your instance.
>What degree of paralellism on this table would be preferable?
See your Concepts manual.
>
>Thank you!
>
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--
These opinions are my own and not necessarily those of Information Quest
or Pebble In The Sky http://www.informationquest.com http://ourworld.compuserve.com/homepages/joel_garry jgarry@nospameiq.com "See your DBA?" I AM the @#%*& DBA! Remove nospam to reply. Sorry.Received on Mon May 18 1998 - 14:30:20 CDT
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