Re: Performance bug in prepared statement binding in 9.2?

On 2013-09-11 11:35:45 -0700, Josh Berkus wrote:
> All,
>
> We've confirmed that this issue is caused by having long-running idle
> transactions on the server.  When we disabled their queueing system
> (which prodiced hour-long idle txns), the progressive slowness went away.
>
> Why that should affect 9.X far more strongly than 8.4, I'm not sure
> about.  Does that mean that 8.4 was unsafe, or that this is something
> which *could* be fixed in later versions?

The explanation is in
http://archives.postgresql.org/message-id/20130910132133.GJ1024477%40alap2.anarazel.de

The referenced commit introduced a planner feature. Funnily you seem to
have been the trigger for it's introduction ;)

> I'm also confused as to why this would affect BIND time rather than
> EXECUTE time.

Because we're doing the histogram checks during planning and not during
execution.

Greetings,

Andres Freund

--
 Andres Freund                       http://www.2ndQuadrant.com/
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