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From: tv@fuzzy.cz
To: Humair Mohammed <humairm@hotmail.com>
Cc: pgsql-performance@postgresql.org
Subject: Re: Query Performance SQL Server vs. Postgresql
Date: Sun, 21 Nov 2010 15:34:46 +0100
Message-ID: <ef40ef98515c88b82f63c7d6cc421f12.squirrel@sq.gransy.com> (raw)
In-Reply-To: <COL115-W5263E5369E2BD0B28E78B9A83C0@phx.gbl>
References: <COL115-W5250BF8BDC50E0A64DABE4A8360@phx.gbl>
	<AANLkTin+MPhrYUzkCZjdAMLhF3KKZCCuvDm0=Npf9jz7@mail.gmail.com>
	<COL115-W3987D9D7DE908C5C47792DA8380@phx.gbl>
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	<COL115-W186A7B93051E6907958ED6A8380@phx.gbl>
	<AANLkTinQmaQ5Ui-vQwfqWFtOTCj76NWFBr6VDKMdVUCs@mail.gmail.com>
	<COL115-W5263E5369E2BD0B28E78B9A83C0@phx.gbl>

> 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.

Tomas

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  To: pgsql-performance@postgresql.org
  Cc: tv@fuzzy.cz, humairm@hotmail.com
  Subject: Re: Query Performance SQL Server vs. Postgresql
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