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Re: Query Performance SQL Server vs. Postgresql

From: tv(at)fuzzy(dot)cz
To: "Humair Mohammed" <humairm(at)hotmail(dot)com>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Query Performance SQL Server vs. Postgresql
Date: 2010-11-21 15:42:07
Message-ID: 1cc426dab35a9fc3fd189d5f9a6fb7a0.squirrel@sq.gransy.com (view raw or flat)
Thread:
Lists: pgsql-performance
>> 4) INDEXESI can certainly add an index but given the table sizes I am
>> not
>> sure if that is a factor. This by no means is a large dataset less than
>> 350,000 rows in total and 3 columns. Also this was just a quick dump of
>> data for comparison purpose. When I saw the poor performance on the
>> COALESCE, I pointed the data load to SQL Server and ran the same query
>> except with the TSQL specific ISNULL function.
>
> 350000 rows definitely is a lot of rows, although with 3 INT column it's
> just about 13MB of data (including overhead). But indexes can be quite
> handy when doing joins, as in this case.

OK, I've just realized the tables have 3 character columns, not integers.
In that case the tables are probably much bigger (and there are things
like TOAST). In that case indexes may be even more important.

Tomas


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