Re: What value Oracle uses for db_cache_size when making decision on direct path reads if db_cache_size isn't set?

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Sat, 16 Aug 2014 03:16:16 +0000 (UTC)
Message-ID: <pan.2014.08.16.03.16.15_at_gmail.com>


On Thu, 14 Aug 2014 04:37:08 -0700, vsevolod afanassiev wrote:

> It is known that from 11.2.02 Oracle would use direct path reads when
> doing full table scan if table size exceeds certain percentage of the
> db_cache_size.
>
> Question: if we are using AMM and set memory_target and
> memory_max_target but don't set db_cache_size - what value Oracle would
> use for db_cache_size when deciding whether to use direct path reads of
> buffered reads for a particular table?

I believe that DB_FILE_MULTIBLOCK_READ_COUNT is used. The "strace" utility would be able to give you an answer to that.

-- 
Received on Sat Aug 16 2014 - 05:16:16 CEST

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