Re: Rewrite, normal execution vs. EXPLAIN ANALYZE - Mailing list pgsql-hackers

From Marko Tiikkaja
Subject Re: Rewrite, normal execution vs. EXPLAIN ANALYZE
Date
Msg-id 4C49F6F6.9020300@cs.helsinki.fi
Whole thread Raw
In response to Re: Rewrite, normal execution vs. EXPLAIN ANALYZE  (Andres Freund <andres@anarazel.de>)
List pgsql-hackers
On 7/23/2010 10:46 PM, Andres Freund wrote:
> On Fri, Jul 23, 2010 at 03:30:03PM -0400, Robert Haas wrote:
>> On Fri, Jul 23, 2010 at 3:19 PM, Marko Tiikkaja
>> <marko.tiikkaja@cs.helsinki.fi>  wrote:
>>> This may be a bit hard to follow, but essentially what happens is that in
>>> EXPLAIN ANALYZE, the INSERT in the rule does not see the changes made by T2
>>> to baz while in the regular execution scenario it does.
>>
>> Well that's gotta be a bug, but in what I'm not sure.
> One could argue that its less of a semantic change changing explain's
> behaviour than the normal executors way of working...

One could also argue that people usually test their code with EXPLAIN 
ANALYZE and could've made the opposite conclusion based on its output. ;-)

But I really have no idea what we should do about this.  It seems to me 
that EXPLAIN ANALYZE's behaviour is less surprising (that's actually 
what I, before yesterday, always thought happens), but I'm not too sure 
about that either.


Regards,
Marko Tiikkaja


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