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Re: Slow query after upgrades

From: Oliver Jowett <oliver(at)opencloud(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: Tom Duffey <tduffey(at)techbydesign(dot)com>, pgsql-jdbc(at)postgresql(dot)org
Subject: Re: Slow query after upgrades
Date: 2007-12-13 23:54:41
Message-ID: 4761C641.30308@opencloud.com (view raw or flat)
Thread:
Lists: pgsql-jdbc
Tom Lane wrote:

> It looks pretty obvious from the peanut gallery: in the parameterized
> query, the planner daren't choose an indexscan, because for the vast
> majority of the possible values of the parameter an indexscan would
> suck.

The JDBC driver is using an unnamed statement in this case, shouldn't 
the planner end up using index selectivity estimates based on the actual 
parameter values?

 From the explain output that just came through it looks like a type 
mismatch problem on the timestamp parameter.

-O

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