Re: add_path optimization

>> Running a complex query (posted in previous threads, runs about
>> 300,000 time per day in a production web application), I got these
>> timings on a production quality machine (4 quad CPU chips, that is 16
>> CPUs like this: Intel(R) Xeon(R) CPU  X7350 @ 2.93GHz, 128 GB RAM, big
>> RAID with BBU).  I ran explain in each environment 5 times, tossed
>> high and low, and averaged.  The 8.4devel was from today's
>> (2008-02-02) snapshot, built the same way we did 8.3.5.
>>
>> 8.3.5, statistics target 10:  36.188 ms
>> 8.4devel without patch, statistics target 100:  109.862 ms
>> 8.4devel with patch, statistics target 100:  104.015 ms
>>
>> After seeing that, I re-analyzed to eliminate the statistics target as
>> the cause of the 8.4 increase.
>>
>> 8.4devel with patch, statistics target 10:  99.421 ms
>
> Yikes!  The impact of the patch is about what I'd expect, but the fact
> that planning time has nearly tripled is... way poor.  Can you repost
> the query and the EXPLAIN output for 8.3.5 and CVS HEAD?

FYI, I retested my queries on REL8_3_STABLE and the results were not
all that different from CVS HEAD.  So the problem is apparently
specific to something your query is doing that mine isn't., rather
than a general slowdown in planning (or else one of us goofed up the
testing).

...Robert