postgresql is slow with larger table even it is in RAM - Mailing list pgsql-admin

From sathiya psql
Subject postgresql is slow with larger table even it is in RAM
Date
Msg-id f966c2ee0803250136j2b44a10j4fb54afbee3ed8ed@mail.gmail.com
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Responses Re: postgresql is slow with larger table even it is in RAM  ("Uwe C. Schroeder" <uwe@oss4u.com>)
Re: postgresql is slow with larger table even it is in RAM  (CZUCZY Gergely <gergely.czuczy@harmless.hu>)
List pgsql-admin
Dear Friends,
     I have a table with 32 lakh record in it. Table size is nearly 700 MB, and my machine had a 1 GB + 256 MB RAM, i had created the table space in RAM, and then created this table in this RAM.

    So now everything is in RAM, if i do a count(*) on this table it returns 327600 in 3 seconds, why it is taking 3 seconds ????? because am sure that no Disk I/O is happening. ( using vmstat i had confirmed, no disk I/O is happening, swap is also not used )

Any Idea on this ???

I searched a lot in newsgroups ... can't find relevant things.... ( because everywhere they are speaking about disk access speed, here i don't want to worry about disk access )

If required i will give more information on this.

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