pg.ddx.io  pgsql-performance@postgresql.org mailing list archive  
help / color / mirror / Atom feed
From: Gregory Stark <stark@enterprisedb.com>
To: Martijn van Oosterhout <kleptog@svana.org>
Cc: Simon Riggs <simon@2ndquadrant.com>
Cc: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Kelly Burkhart <kelly.burkhart@gmail.com>
Cc: Evgeny Gridasov <eugrid@fpm.kubsu.ru>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-hackers@postgresql.org
Subject: Re: [PERFORM] EXPLAIN ANALYZE on 8.2
Date: Fri, 15 Dec 2006 12:15:59 +0000
Message-ID: <87irgdiccg.fsf@enterprisedb.com> (raw)
In-Reply-To: <20061215105008.GD958@svana.org>
References: <20061214163230.d46f0138.eugrid@fpm.kubsu.ru>
	<21146.1166112702@sss.pgh.pa.us>
	<20061214192920.c75385d6.eugrid@fpm.kubsu.ru>
	<21516.1166114475@sss.pgh.pa.us>
	<fa1e4ce70612141543o8866d7fg417eca88ce9b1344@mail.gmail.com>
	<29450.1166141131@sss.pgh.pa.us>
	<1166178488.3882.56.camel@silverbirch.site>
	<20061215105008.GD958@svana.org>

"Martijn van Oosterhout" <kleptog@svana.org> writes:

> BTW, doing gettimeofday() without kernel entry is not really possible.

That's too strong a conclusion. Doing gettimeofday() without some help from
the kernel isn't possible but it isn't necessary to enter the kernel for each
call.

There are various attempts at providing better timing infrastructure at low
overhead but I'm not sure what's out there currently. I expect to do this what
we'll have to do is invent a pg_* abstraction that has various implementations
on different architectures. On Solaris it can use DTrace internally, on Linux
it might have something else (or more likely several different options
depending on the age and config options of the kernel). 

-- 
  Gregory Stark
  EnterpriseDB          http://www.enterprisedb.com



view thread (24+ messages)  latest in thread

Message-ID: <87irgdiccg.fsf@enterprisedb.com>
Permalink:  ../87irgdiccg.fsf@enterprisedb.com/
Also on:    postgresql.org/message-id/87irgdiccg.fsf@enterprisedb.com

 · 

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: pgsql-performance@postgresql.org
  Cc: stark@enterprisedb.com, kleptog@svana.org, simon@2ndquadrant.com, tgl@sss.pgh.pa.us, kelly.burkhart@gmail.com, eugrid@fpm.kubsu.ru, pgsql-hackers@postgresql.org
  Subject: Re: [PERFORM] EXPLAIN ANALYZE on 8.2
  In-Reply-To: <87irgdiccg.fsf@enterprisedb.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox