Re: [GENERAL] 8.2.4 serious slowdown

On Jan 10, 2008 9:50 AM, Clodoaldo <clodoaldo.pinto.neto@gmail.com> wrote:
> 2008/1/10, Sim Zacks <sim@compulab.co.il>:
> > I just upgraded my database server from 8.0.1 to 8.2.4
> > Most things went very well, but I have a couple of queries that really slowed down with the new server.
> > On 8.0.1 the query took less then 3 seconds to complete. On 8.2.4 the same query
> > (I vacuumed the database before running the query) takes 60 seconds (10 minutes with Explain Analyze).
> >
> > The data is exactly the same on the 2 servers.
> >
> > To test for hardware differences, I loaded 8.0.11 onto a test server restored the database and ran the query.
> > It took about 3 seconds. I then uninstalled postgresql and installed version 8.2.4 and restored the database
> > and the query took about 60 seconds.
> >
> > On the 8.2.4 the CPU usage (as seen from top) goes up to about 97% for most of the 60 seconds of query.
> > On 8.0.1, it didn't.
> >
> > I have the explain from both databases, if someone could help me walk through this, I would much appreciate it.
>
> I have seen performance degradation at every new version since 7.3.

Then your experience has been exactly the opposite of mine.

> But now 8.3 is a complete disaster. It could be that my most expensive
> query is just a corner case, but I don't believe it.

So, what's the other explanation, all queries in 8.3 are slower, and everyone who says it's faster is just lieing?

> Could you try 8.3 and see what happens? Keep the emails in case this
> thread mysteriously disappears.

Please stop the histrionics. If your new query is slower, post the information here to help the hackers figure out why its slower and help you fix it. There's no grand conspiracy to hide you poorly performing query. There may be a negative reaction to your behaviour that's hampering it getting any priority to get fixed, but I can't say I'd blame the hackers on that one.

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               http://archives.postgresql.org/ Received on Thu Jan 10 11:44:34 2008