On Mon, 30 Aug 2010, Scott Marlowe wrote:
> On Mon, Aug 30, 2010 at 12:20 AM, Gerhard Wiesinger <lists(at)wiesinger(dot)com> wrote:
>> I just upgraded with pg_dump/restore from PostgreSQL 8.3.11 to 8.4.4 but I'm
>> having major performance problems with a query with many left joins. Problem
>> is that costs are now very, very, very high (was ok in 8.3). Analyze has
>> been done. Indexes are of course there.
>> -> Merge Left Join
>> Merge Cond: (l.id = d2000903.fk_id)
> Wow! Other than an incredibly high cost AND row estimate, was the
> query plan the same on 8.3 or different?
>> Details with execution plan can be found at:
> What's up with the "(actual time=.. rows= loops=) " in the explain analyze?
What do you mean exactly? missing?
I did it not with psql but with a GUI program.
>> I know that the data model is key/value pairs but it worked well in 8.3. I
>> need this flexibility.
>> Any ideas?
> Not really. I would like an explain analyze from both 8.3 and 8.4.
> Are they tuned the same, things like work mem and default stats
I don't have a 8.3 version running anymore. But I'm havin an OLD version
of a nearly exactly query plan (The sort was missing due to performance
issues and it done now in a view, maybe also some more JOINS are added,
but all that doesn't have impacts on the basic principle of the query
Tuning: Yes, on same machine with same parameters (manual diff on old
config and added manually the parameters again).
In response to
pgsql-performance by date
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