Re: [pgsql-performance] [GENERAL] Large databases, performance - Mailing list pgsql-hackers

From Tom Lane
Subject Re: [pgsql-performance] [GENERAL] Large databases, performance
Date
Msg-id 23489.1034001037@sss.pgh.pa.us
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In response to Re: [GENERAL] Large databases, performance  ("Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>)
Responses Re: [pgsql-performance] [GENERAL] Large databases, performance  ("Shridhar Daithankar" <shridhar_daithankar@persistent.co.in>)
List pgsql-hackers
"Shridhar Daithankar" <shridhar_daithankar@persistent.co.in> writes:
> MySQL 3.23.52 with innodb transaction support:

> 4 concurrent queries     :-  257.36 ms
> 40 concurrent queries    :-  35.12 ms

> Postgresql 7.2.2

> 4 concurrent queries         :- 257.43 ms
> 40 concurrent     queries        :- 41.16 ms

I find this pretty fishy.  The extreme similarity of the 4-client
numbers seems improbable, from what I know of the two databases.
I suspect your numbers are mostly measuring some non-database-related
overhead --- communications overhead, maybe?

> Only worry is database size. Postgresql is 111GB v/s 87 GB for mysql. All
> numbers include indexes. This is really going to be a problem when things are
> deployed. Any idea how can it be taken down?

7.3 should be a little bit better because of Manfred's work on reducing
tuple header size --- if you create your tables WITHOUT OIDS, you should
save 8 bytes per row compared to earlier releases.

            regards, tom lane

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