Re: [COMMITTERS] pgsql: Teach tuplesort.c about "top N" sorting, in which only the first - Mailing list pgsql-hackers

From Jim Nasby
Subject Re: [COMMITTERS] pgsql: Teach tuplesort.c about "top N" sorting, in which only the first
Date
Msg-id ED48CE35-22B1-421C-8956-81EBD50AA45C@decibel.org
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In response to Re: [COMMITTERS] pgsql: Teach tuplesort.c about "top N" sorting, in which only the first  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: [COMMITTERS] pgsql: Teach tuplesort.c about "top N" sorting, in which only the first  (Alvaro Herrera <alvherre@commandprompt.com>)
List pgsql-hackers
On May 6, 2007, at 9:32 AM, Tom Lane wrote:
> Jim Nasby <decibel@decibel.org> writes:
>> There's several problems with that. First, trace_sort isn't
>> documented (or at least it's not in postgresql.conf), so most folks
>> don't know it exists. Second, in order to see it's output you have to
>> drop log_min_messages to debug. That results in a huge log volume,
>> especially on a production system.
>
> Nonsense ... trace_sort output is at LOG level.

I stand corrected. But my point still remains. It wouldn't be unusual  
for a website database to be running several sorts a second; that  
means 4 lines per sort, which is still a large amount of data.

If we really want to make the logfile the approved method for  
monitoring performance, then why do we have the stats infrastructure  
at all? It could all be replaced with logging output and pgfouine.

Why are we maintaining two separate sets of code for monitoring  
database performance?
--
Jim Nasby                                            jim@nasby.net
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)




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