Re: Cache a table

From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Mon, 27 Oct 2003 07:50:00 -0000
Message-ID: <bniil7$krs$1$8300dec7@news.demon.co.uk>

Certainly an argument in favour. But only if the tablescans are very frequent - then you have to ensure that the KEEP cache is large enough to hold all relevant objects.

However, if the database is running on buffered file system, then the cost of re-reading from file system might not be significant compared to other 'real' reads.

On the other hand, if you are doing extremely regular tablescans, you might ask why, and whether the correct solution is to use indexed access anyway.

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"Geomancer" <pharfromhome_at_hotmail.com> wrote in message
news:cf90fb89.0310261909.75c1616c_at_posting.google.com...


> If this is correct (Jonathan is seldom wrong!), then it would imply

> that rows from small table full table scans would be re-read many

> times as they age-out of the LRU end of the buffer.

>

> This might cause unnecessary disk I/O.

>

> Would this be justification for caching all small tables that

> experience full table scans in the KEEP pool?

Received on Mon Oct 27 2003 - 01:50:00 CST