Re: POSIX regex performance bug in 7.3 Vs. 7.2

At 05:51 PM 2/3/03 -0500, Tom Lane wrote:
>wade <wade@wavefire.com> writes:
>> Here is the profile information.  I included a log of the session that
>> generated it at the top of the gprof  output.  If there is any other info I
>> can help you with, please let me know.
>
>A four-second test isn't long enough to gather any statistically
>meaningful profile info.  On most machines, gprof samples 100 times per
>second, so realistically you need a minute or two of runtime to have
>trustworthy numbers.
>
>Please replicate the rows in the table by a factor of ten or twenty or
>so and try again.
>
>            regards, tom lane
OK, here goes again.
I have tried a different table, this one with 27444 rows.
In this case, the query with the regex of the form "row ~* 'regex'"
runs in 1.113 seconds and the other runs in 600.
The session idled for a while after the query completed if that makes a
difference.
Queries and explain output are included at the top of the gprof output.
http://arch.wavefire.com/pgregexgmon.txt -Wade Klaver