mirror/postgresql
2
0
Fork 0
mirror of https://git.postgresql.org/git/postgresql.git synced 2025-01-12 18:34:36 +08:00
Code Issues Packages Projects Releases Wiki Activity
0cd8cb1a03
postgresql/doc/TODO.detail/namedatalen

1071 lines
40 KiB
Plaintext
Raw Normal View History

Add discussion.
2002-02-22 11:04:48 +08:00
From pgsql-hackers-owner+M18800=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 15:25:43 2002
Return-path: <pgsql-hackers-owner+M18800=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1DKPgP09129
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 15:25:42 -0500 (EST)
Received: (qmail 83025 invoked by alias); 13 Feb 2002 20:25:41 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 13 Feb 2002 20:25:41 -0000
Received: from h97.c194.tor.velocet.net (H97.C194.tor.velocet.net [216.138.194.97])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1DK7kE77269
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 15:07:47 -0500 (EST)
(envelope-from rbt@zort.ca)
Received: (qmail 41141 invoked by uid 0); 13 Feb 2002 20:07:41 -0000
Received: from h97.c194.tor.velocet.net (HELO jester) (216.138.194.97)
by 192.168.1.11 with RC4-MD5 encrypted SMTP; 13 Feb 2002 20:07:41 -0000
Message-ID: <003901c1b4ca$1d762500$8001a8c0@jester>
From: "Rod Taylor" <rbt@zort.ca>
To: "Hackers List" <pgsql-hackers@postgresql.org>
Subject: [HACKERS] NAMEDATALEN Changes
Date: Wed, 13 Feb 2002 15:07:50 -0500
MIME-Version: 1.0
Content-Type: multipart/mixed;
boundary="----=_NextPart_000_0036_01C1B4A0.343E4DF0"
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
This is a multi-part message in MIME format.
------=_NextPart_000_0036_01C1B4A0.343E4DF0
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
NAMEDATALEN's benchmarked are 32, 64, 128 and 512. Attached is the
shell script I used to do it.
First row of a set is the time(1) for the pgbench -i run, second is
the actual benchmark. Aside from the 'real' time of 64 there is a
distinct increase in time required, but not significant.
Benchmarks were run for 3000 transactions with scale factor of 5, but
only 1 client. If there is a preferred setting for pgbench I can do
an overnight run with it. Machine is a dual 500Mhz celery with 384MB
ram and 2 IBM Deskstars in Raid 0, and a seperate system drive.
Anything but 32 fails the 'name' check in the regression tests -- I
assume this is expected?
Don't know why 64 has a high 'real' time, but the system times are
appropriate.
NAMEDATALEN: 32
158.97 real 1.81 user 0.14 sys
80.58 real 1.30 user 3.81 sys
NAMEDATALEN: 64
248.40 real 1.85 user 0.10 sys
96.36 real 1.44 user 3.86 sys
NAMEDATALEN: 128
156.74 real 1.84 user 0.10 sys
94.36 real 1.47 user 4.01 sys
NAMEDATALEN: 512
157.99 real 1.83 user 0.12 sys
101.14 real 1.47 user 4.23 sys
--
Rod Taylor
Your eyes are weary from staring at the CRT. You feel sleepy. Notice
how restful it is to watch the cursor blink. Close your eyes. The
opinions stated above are yours. You cannot imagine why you ever felt
otherwise.
------=_NextPart_000_0036_01C1B4A0.343E4DF0
Content-Type: application/octet-stream; name="datalenbench.sh"
Content-Transfer-Encoding: quoted-printable
Content-Disposition: attachment; filename="datalenbench.sh"
#!/bin/sh
PGSRC=3D/data/buildtree/postgres/postgresql-7.2
PGBASEPORT=3D5400
PGBASEBIN=3D/data/buildtree/postgres/postgres72
LOG=3D/home/rbt/temp/bench_namedatalen.log
for newDATALEN in 32 64 128 512 ; do
PGBIN=3D${PGBASEBIN}_${newDATALEN}
PGPORT=3D`echo "${PGBASEPORT}+${newDATALEN}" | bc`
sed -E 's/NAMEDATALEN\s[0-9]+/NAMEDATALEN ${newDATALEN}/g' ${PGSRC}/src/i=
nclude/postgres_ext.h > ${PGSRC}/src/include/postgres_ext.h.tmp
mv ${PGSRC}/src/include/postgres_ext.h.tmp ${PGSRC}/src/include/postgres_=
ext.h
cd ${PGSRC}
./configure --prefix=3D${PGBIN} --with-pgport=3D${PGPORT} || (echo "UNABL=
E TO CONFIGURE"; exit)
make clean
make clean install
cd ${PGSRC}/contrib/pgbench
gmake install
${PGBIN}/bin/initdb -D ${PGBIN}/data || (echo "UNABLE TO INITIALIZE"; ex=
it 1)
${PGBIN}/bin/pg_ctl -D ${PGBIN}/data start || (echo "UNABLE TO START"; e=
xit 1)
sleep 5
echo "NAMEDATALEN: ${newDATALEN}" >> ${LOG}
echo >> ${LOG}
time -a -o ${LOG} ${PGBIN}/bin/pgbench -i -s 5 -d template1 -p ${PGPORT}
time -a -o ${LOG} ${PGBIN}/bin/pgbench -t 3000 -s 5 -d template1 -p ${PGP=
ORT}
echo >> ${LOG}
echo >> ${LOG}
${PGBIN}/bin/pg_ctl -D ${PGBIN}/data stop
rm -rf ${PGBIN}
done
------=_NextPart_000_0036_01C1B4A0.343E4DF0
Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/users-lounge/docs/faq.html
------=_NextPart_000_0036_01C1B4A0.343E4DF0--
From pgsql-hackers-owner+M18806=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 17:13:45 2002
Return-path: <pgsql-hackers-owner+M18806=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1DMDiP15852
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 17:13:44 -0500 (EST)
Received: (qmail 13525 invoked by alias); 13 Feb 2002 22:12:53 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 13 Feb 2002 22:12:53 -0000
Received: from sss.pgh.pa.us ([192.204.191.242])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1DLsHE09337
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 16:54:17 -0500 (EST)
(envelope-from tgl@sss.pgh.pa.us)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.11.4/8.11.4) with ESMTP id g1DLrmf00943;
Wed, 13 Feb 2002 16:53:49 -0500 (EST)
To: "Rod Taylor" <rbt@zort.ca>
cc: "Hackers List" <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] NAMEDATALEN Changes
In-Reply-To: <003901c1b4ca$1d762500$8001a8c0@jester>
References: <003901c1b4ca$1d762500$8001a8c0@jester>
Comments: In-reply-to "Rod Taylor" <rbt@zort.ca>
message dated "Wed, 13 Feb 2002 15:07:50 -0500"
Date: Wed, 13 Feb 2002 16:53:48 -0500
Message-ID: <940.1013637228@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
"Rod Taylor" <rbt@zort.ca> writes:
> [ some hard data ]
Great! The numbers for namedatalen = 64 seem like an outlier; perhaps
something else going on on your system? Did you try more than one run?
> Anything but 32 fails the 'name' check in the regression tests -- I
> assume this is expected?
Right. If you eyeball the actual diffs for the test you should see that
the diff is due to a long name not getting truncated where the test
expects it to be.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly
From pgsql-hackers-owner+M18805=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 17:13:39 2002
Return-path: <pgsql-hackers-owner+M18805=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1DMDcP15802
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 17:13:39 -0500 (EST)
Received: (qmail 13545 invoked by alias); 13 Feb 2002 22:12:54 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 13 Feb 2002 22:12:54 -0000
Received: from h97.c194.tor.velocet.net (H97.C194.tor.velocet.net [216.138.194.97])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1DM7iE12735
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 17:07:44 -0500 (EST)
(envelope-from rbt@zort.ca)
Received: (qmail 41562 invoked by uid 0); 13 Feb 2002 22:07:45 -0000
Received: from h97.c194.tor.velocet.net (HELO jester) (216.138.194.97)
by 192.168.1.11 with RC4-MD5 encrypted SMTP; 13 Feb 2002 22:07:45 -0000
Message-ID: <00f501c1b4da$e2f7b7c0$8001a8c0@jester>
From: "Rod Taylor" <rbt@zort.ca>
To: "Tom Lane" <tgl@sss.pgh.pa.us>
cc: "Hackers List" <pgsql-hackers@postgresql.org>
References: <003901c1b4ca$1d762500$8001a8c0@jester> <940.1013637228@sss.pgh.pa.us>
Subject: Re: [HACKERS] NAMEDATALEN Changes
Date: Wed, 13 Feb 2002 17:07:54 -0500
MIME-Version: 1.0
Content-Type: text/plain;
charset="iso-8859-1"
Content-Transfer-Encoding: 7bit
X-Priority: 3
X-MSMail-Priority: Normal
X-Mailer: Microsoft Outlook Express 6.00.2600.0000
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
> > Great! The numbers for namedatalen = 64 seem like an outlier;
perhaps
> something else going on on your system? Did you try more than one
run?
Ran it again shortly after sending the email. It fell in line (mid
way between 32 and 128) with Real time as would normally be expected.
The times for the other values and 64's system times were very close
to the original so I won't bother posting them again.
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/users-lounge/docs/faq.html
From pgsql-hackers-owner+M18807=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 17:58:53 2002
Return-path: <pgsql-hackers-owner+M18807=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1DMwqP19126
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 17:58:52 -0500 (EST)
Received: (qmail 26752 invoked by alias); 13 Feb 2002 22:58:21 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 13 Feb 2002 22:58:21 -0000
Received: from post.webmailer.de (natwar.webmailer.de [192.67.198.70])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1DMRoE22486
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 17:27:51 -0500 (EST)
(envelope-from barwick@gmx.net)
Received: from there (pD9EB1E9E.dip.t-dialin.net [217.235.30.158])
by post.webmailer.de (8.9.3/8.8.7) with SMTP id XAA22201;
Wed, 13 Feb 2002 23:27:16 +0100 (MET)
Message-ID: <200202132227.XAA22201@post.webmailer.de>
From: Ian Barwick <barwick@gmx.net>
To: "Rod Taylor" <rbt@zort.ca>, "Hackers List" <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] NAMEDATALEN Changes
Date: Wed, 13 Feb 2002 23:27:08 +0100
X-Mailer: KMail [version 1.3.1]
References: <003901c1b4ca$1d762500$8001a8c0@jester>
In-Reply-To: <003901c1b4ca$1d762500$8001a8c0@jester>
MIME-Version: 1.0
Content-Type: Multipart/Mixed;
boundary="------------Boundary-00=_81THUZ3BONDS8SCE1A8O"
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
--------------Boundary-00=_81THUZ3BONDS8SCE1A8O
Content-Type: text/plain; charset="iso-2022-jp"
Content-Transfer-Encoding: 8bit
On Wednesday 13 February 2002 21:07, Rod Taylor wrote:
> NAMEDATALEN's benchmarked are 32, 64, 128 and 512. Attached is the
> shell script I used to do it.
Attached is a modified version for Linux, if anyone is interested.
Will run it overnight out of quasi-scientific interest.
Nice to have an idea what kind of effect my very long NAMEDATALEN setting
(128) has.
Yours
Ian Barwick
--------------Boundary-00=_81THUZ3BONDS8SCE1A8O
Content-Type: application/x-shellscript; name="datalenbench.sh"
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="datalenbench.sh"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--------------Boundary-00=_81THUZ3BONDS8SCE1A8O
Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
--------------Boundary-00=_81THUZ3BONDS8SCE1A8O--
From pgsql-hackers-owner+M18811=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 19:13:40 2002
Return-path: <pgsql-hackers-owner+M18811=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1E0DdP24221
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 19:13:39 -0500 (EST)
Received: (qmail 40165 invoked by alias); 14 Feb 2002 00:13:34 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 00:13:34 -0000
Received: from student.gvsu.edu ([148.61.7.124])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1E0ABE39822
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 19:10:11 -0500 (EST)
(envelope-from peter_e@gmx.net)
Received: from [148.61.250.151] [148.61.250.151] by student.gvsu.edu
with Novonyx SMTP Server $Revision: 1.1 $; Wed, 13 Feb 2002 19:10:16 -0500 (EDT)
Date: Wed, 13 Feb 2002 19:12:57 -0500 (EST)
From: Peter Eisentraut <peter_e@gmx.net>
X-Sender: <peter@peter.localdomain>
To: Rod Taylor <rbt@zort.ca>
cc: Hackers List <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] NAMEDATALEN Changes
In-Reply-To: <003901c1b4ca$1d762500$8001a8c0@jester>
Message-ID: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
Rod Taylor writes:
> NAMEDATALEN's benchmarked are 32, 64, 128 and 512. Attached is the
> shell script I used to do it.
That's around a 15% performance loss for increasing it to 64 or 128.
Seems pretty scary actually.
--
Peter Eisentraut peter_e@gmx.net
---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
From pgsql-hackers-owner+M18815=candle.pha.pa.us=pgman@postgresql.org Wed Feb 13 20:02:31 2002
Return-path: <pgsql-hackers-owner+M18815=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1E12TP29895
for <pgman@candle.pha.pa.us>; Wed, 13 Feb 2002 20:02:29 -0500 (EST)
Received: (qmail 49786 invoked by alias); 14 Feb 2002 01:02:26 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 01:02:26 -0000
Received: from sss.pgh.pa.us ([192.204.191.242])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1E10oE49562
for <pgsql-hackers@postgresql.org>; Wed, 13 Feb 2002 20:00:50 -0500 (EST)
(envelope-from tgl@sss.pgh.pa.us)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.11.4/8.11.4) with ESMTP id g1E107f04416;
Wed, 13 Feb 2002 20:00:07 -0500 (EST)
To: Peter Eisentraut <peter_e@gmx.net>
cc: Rod Taylor <rbt@zort.ca>, Hackers List <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] NAMEDATALEN Changes
In-Reply-To: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain>
References: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain>
Comments: In-reply-to Peter Eisentraut <peter_e@gmx.net>
message dated "Wed, 13 Feb 2002 19:12:57 -0500"
Date: Wed, 13 Feb 2002 20:00:06 -0500
Message-ID: <4413.1013648406@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
Peter Eisentraut <peter_e@gmx.net> writes:
> That's around a 15% performance loss for increasing it to 64 or 128.
> Seems pretty scary actually.
Some of that could be bought back by fixing hashname() to not iterate
past the first \0 when calculating the hash of a NAME datum; and then
cc_hashname could go away. Not sure how much this would buy though.
Looking closely at Rod's script, I realize that the user+sys times it is
reporting are not the backend's but the pgbench client's. So it's
impossible to tell from this how much of the extra cost is extra I/O and
how much is CPU. I'm actually quite surprised that the client side
shows any CPU-time difference at all; I wouldn't think it ever sees any
null-padded NAME values.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly
From pgsql-hackers-owner+M18817=candle.pha.pa.us=pgman@postgresql.org Thu Feb 14 01:22:04 2002
Return-path: <pgsql-hackers-owner+M18817=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1E6M3P26219
for <pgman@candle.pha.pa.us>; Thu, 14 Feb 2002 01:22:03 -0500 (EST)
Received: (qmail 83168 invoked by alias); 14 Feb 2002 06:22:05 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 06:22:05 -0000
Received: from klamath.dyndns.org (CPE002078144ae0.cpe.net.cable.rogers.com [24.102.202.35])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1E5xfE81904
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 00:59:41 -0500 (EST)
(envelope-from nconway@klamath.dyndns.org)
Received: from localhost.localdomain (jiro [192.168.40.7])
by klamath.dyndns.org (Postfix) with ESMTP id 11D2E7007
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 00:59:41 -0500 (EST)
Subject: Re: [HACKERS] NAMEDATALEN Changes
From: Neil Conway <nconway@klamath.dyndns.org>
To: pgsql-hackers@postgresql.org
In-Reply-To: <4413.1013648406@sss.pgh.pa.us>
References: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain>
<4413.1013648406@sss.pgh.pa.us>
Content-Type: multipart/mixed; boundary="=-0nvLRoTY5hWeegGhITre"
X-Mailer: Evolution/1.0.2
Date: 14 Feb 2002 00:59:40 -0500
Message-ID: <1013666380.5380.19.camel@jiro>
MIME-Version: 1.0
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: ORr
--=-0nvLRoTY5hWeegGhITre
Content-Type: text/plain
Content-Transfer-Encoding: 7bit
On Wed, 2002-02-13 at 20:00, Tom Lane wrote:
> Peter Eisentraut <peter_e@gmx.net> writes:
> > That's around a 15% performance loss for increasing it to 64 or 128.
> > Seems pretty scary actually.
>
> Some of that could be bought back by fixing hashname() to not iterate
> past the first \0 when calculating the hash of a NAME datum; and then
> cc_hashname could go away. Not sure how much this would buy though.
I've attached a pretty trivial patch that implements this. Instead of
automatically hashing NAMEDATALEN bytes, hashname() uses only strlen()
bytes: this should improve both the common case (small identifers, 5-10
characters long), as well as reduce the penalty when NAMEDATALEN is
increased. The patch passes the regression tests, FWIW. I didn't remove
cc_hashname() -- I'll tackle that tomorrow unless anyone objects...
I also did some pretty simple benchmarks; however, I'd appreciate it
anyone could confirm these results.
pg_bench: scale factor 1, 1 client, 10000 transactions.
hardware: p3-850, 384 MB RAM, slow laptop IDE disk
Run 1: Patch applied, NAMEDATALEN = 32
number of transactions actually processed: 10000/10000
tps = 19.940020(including connections establishing)
tps = 19.940774(excluding connections establishing)
Run 2: Patch applied, NAMEDATALEN = 128
number of transactions actually processed: 10000/10000
tps = 20.849385(including connections establishing)
tps = 20.850010(excluding connections establishing)
Run 3: Vanilla CVS, NAMEDATALEN = 32
(This is to check that the patch doesn't cause performance regressions
for the "common case")
number of transactions actually processed: 10000/10000
tps = 18.295418(including connections establishing)
tps = 18.296191(excluding connections establishing)
The performance improvement @ NAMEDATALEN = 128 seems strange. As I
said, these benchmarks may not be particularly accurate, so I'd suggest
waiting for others to contribute results before drawing any conclusions.
Oh, and this is my first "real" Pg patch, so my apologies if I've
screwed something up. ;-)
Cheers,
Neil
--
Neil Conway <neilconway@rogers.com>
PGP Key ID: DB3C29FC
--=-0nvLRoTY5hWeegGhITre
Content-Disposition: attachment; filename=hash_len.patch
Content-Transfer-Encoding: quoted-printable
Content-Type: text/x-patch; charset=ISO-8859-1
*** ./src/backend/access/hash/hashfunc.c.orig Wed Feb 13 21:09:37 2002
--- ./src/backend/access/hash/hashfunc.c Thu Feb 14 00:39:42 2002
***************
*** 95,101 ****
{
char *key =3D NameStr(*PG_GETARG_NAME(0));
=20=20
! return hash_any((char *) key, NAMEDATALEN);
}
=20=20
/*
--- 95,101 ----
{
char *key =3D NameStr(*PG_GETARG_NAME(0));
=20=20
! return hash_any(key, strlen(key));
}
=20=20
/*
***************
*** 125,131 ****
*
* (Comment from the original db3 hashing code: )
*
! * "This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
* units. On the first time through the loop we get the 'leftover bytes'
* (strlen % 8). On every later iteration, we perform 8 HASHC's so we ha=
ndle
* all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. =
If
--- 125,131 ----
*
* (Comment from the original db3 hashing code: )
*
! * This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
* units. On the first time through the loop we get the 'leftover bytes'
* (strlen % 8). On every later iteration, we perform 8 HASHC's so we ha=
ndle
* all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. =
If
***************
*** 134,140 ****
* "OZ's original sdbm hash"
*/
Datum
! hash_any(char *keydata, int keylen)
{
uint32 n;
int loop;
--- 134,140 ----
* "OZ's original sdbm hash"
*/
Datum
! hash_any(const char *keydata, int keylen)
{
uint32 n;
int loop;
*** ./src/include/access/hash.h.orig Wed Feb 13 22:43:06 2002
--- ./src/include/access/hash.h Thu Feb 14 00:38:35 2002
***************
*** 265,271 ****
extern Datum hashint2vector(PG_FUNCTION_ARGS);
extern Datum hashname(PG_FUNCTION_ARGS);
extern Datum hashvarlena(PG_FUNCTION_ARGS);
! extern Datum hash_any(char *keydata, int keylen);
=20=20
=20=20
/* private routines */
--- 265,271 ----
extern Datum hashint2vector(PG_FUNCTION_ARGS);
extern Datum hashname(PG_FUNCTION_ARGS);
extern Datum hashvarlena(PG_FUNCTION_ARGS);
! extern Datum hash_any(const char *keydata, int keylen);
=20=20
=20=20
/* private routines */
--=-0nvLRoTY5hWeegGhITre
Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
---------------------------(end of broadcast)---------------------------
TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
--=-0nvLRoTY5hWeegGhITre--
From pgsql-hackers-owner+M18819=candle.pha.pa.us=pgman@postgresql.org Thu Feb 14 09:03:43 2002
Return-path: <pgsql-hackers-owner+M18819=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1EE3gP17661
for <pgman@candle.pha.pa.us>; Thu, 14 Feb 2002 09:03:42 -0500 (EST)
Received: (qmail 68050 invoked by alias); 14 Feb 2002 14:03:37 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 14:03:37 -0000
Received: from CopelandConsulting.Net (dsl-24293-ld.customer.centurytel.net [209.142.135.135])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1EE1FE67720
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 09:01:15 -0500 (EST)
(envelope-from greg@copelandconsulting.net)
Received: from there (mouse.copelandconsulting.net [192.168.1.2])
by CopelandConsulting.Net (8.10.1/8.10.1) with SMTP id g1EE1Dk24399;
Thu, 14 Feb 2002 08:01:14 -0600 (CST)
Message-ID: <CCC.200202141401.g1EE1Dk24399@CopelandConsulting.Net>
X-Trade-Id: <CCC.Thu, 14 Feb 2002 08:01:14 -0600 (CST).Thu, 14 Feb 2002 08:01:14 -0600 (CST).200202141401.g1EE1Dk24399.g1EE1Dk24399@CopelandConsulting.Net.
Content-Type: text/plain;
charset="iso-8859-1"
From: Greg Copeland <greg@CopelandConsulting.Net>
Organization: Copeland Computer Consulting
To: Neil Conway <nconway@klamath.dyndns.org>, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] NAMEDATALEN Changes
Date: Thu, 14 Feb 2002 08:00:58 -0600
X-Mailer: KMail [version 1.3.1]
References: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain> <4413.1013648406@sss.pgh.pa.us> <1013666380.5380.19.camel@jiro>
In-Reply-To: <1013666380.5380.19.camel@jiro>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On Wednesday 13 February 2002 23:59, Neil Conway wrote:
> On Wed, 2002-02-13 at 20:00, Tom Lane wrote:
[perf hit comment removed]
>
> I've attached a pretty trivial patch that implements this. Instead of
> automatically hashing NAMEDATALEN bytes, hashname() uses only strlen()
> bytes: this should improve both the common case (small identifers, 5-10
> characters long), as well as reduce the penalty when NAMEDATALEN is
> increased. The patch passes the regression tests, FWIW. I didn't remove
> cc_hashname() -- I'll tackle that tomorrow unless anyone objects...
>
> I also did some pretty simple benchmarks; however, I'd appreciate it
> anyone could confirm these results.
>
Please bare with me on this as this is my first posting having any real
content. <20>Please don't hang me out if I've overlooked anything and I'm
pointing out that I'm making a rather large assumption. Please correct as
needed.
The primary assumption is that the actual key lengths can be less than
NAMEDATALEN. That is, if the string, "shortkey" is a valid input key (??)
which provides a key length of 8-bytes as input to the hash_any() function
even though NAMEDATALEN may be something like 128 or larger. If this
assumption is correct, then wouldn't increasing the default input key size
(NAMEDATALEN) beyond the maximum actual key length be a bug? That is to say,
if we have a key with only 8-bytes of data and we iterrate over 128-bytes,
wouldn't the resulting hash be arbitrary and invalid as it would be hashing
memory which is not reflective of the key being hashed?
If my assumptions are correct, then it sounds like using the strlen()
implementation (assuming input keys are valid C-strings) is really the proper
implementation short of using an adjusted min(NAMEDATALEN,strlen()) type
approach.
[snip - var NAMEDATALEN benchmark results]
Greg
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: For info see http://www.gnupg.org
iD8DBQE8a8Mg4lr1bpbcL6kRAlaxAJ47CO+ExL/ZMo/i6LDoetXrul9qqQCfQli3
AvqN6RJjSuAH/p/mpZ8J4JY=
=wnVM
-----END PGP SIGNATURE-----
---------------------------(end of broadcast)---------------------------
TIP 5: Have you checked our extensive FAQ?
http://www.postgresql.org/users-lounge/docs/faq.html
From pgsql-hackers-owner+M18820=candle.pha.pa.us=pgman@postgresql.org Thu Feb 14 10:14:25 2002
Return-path: <pgsql-hackers-owner+M18820=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1EFEOP25217
for <pgman@candle.pha.pa.us>; Thu, 14 Feb 2002 10:14:24 -0500 (EST)
Received: (qmail 80096 invoked by alias); 14 Feb 2002 15:14:19 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 15:14:19 -0000
Received: from sss.pgh.pa.us ([192.204.191.242])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1EEvpE77298
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 09:57:51 -0500 (EST)
(envelope-from tgl@sss.pgh.pa.us)
Received: from sss2.sss.pgh.pa.us (tgl@localhost [127.0.0.1])
by sss.pgh.pa.us (8.11.4/8.11.4) with ESMTP id g1EEvof08568;
Thu, 14 Feb 2002 09:57:50 -0500 (EST)
To: Greg Copeland <greg@CopelandConsulting.Net>
cc: Neil Conway <nconway@klamath.dyndns.org>, pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] NAMEDATALEN Changes
In-Reply-To: <CCC.200202141401.g1EE1Dk24399@CopelandConsulting.Net>
References: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain> <4413.1013648406@sss.pgh.pa.us> <1013666380.5380.19.camel@jiro> <CCC.200202141401.g1EE1Dk24399@CopelandConsulting.Net>
Comments: In-reply-to Greg Copeland <greg@CopelandConsulting.Net>
message dated "Thu, 14 Feb 2002 08:00:58 -0600"
Date: Thu, 14 Feb 2002 09:57:50 -0500
Message-ID: <8565.1013698670@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
Greg Copeland <greg@CopelandConsulting.Net> writes:
> if we have a key with only 8-bytes of data and we iterrate over 128-bytes,
> wouldn't the resulting hash be arbitrary and invalid as it would be hashing
> memory which is not reflective of the key being hashed?
As long as we do it *consistently*, we can do it either way. Using the
trailing nulls in the hash does alter the computed hash value --- but
we're only ever gonna compare the hash value against other hash values
computed on other NAMEs by this same routine.
This all assumes that the inputs are valid NAMEs, viz strlen <
NAMEDATALEN and no funny business beyond the first \0. In practice,
however, if a bogus NAME were handed to us we would just as soon ignore
any characters beyond the first \0, because the ordering comparison
operators for NAME all do so (they're all based on strncmp), as do the
I/O routines etc. So this change actually makes the system more
self-consistent not less so.
regards, tom lane
---------------------------(end of broadcast)---------------------------
TIP 6: Have you searched our list archives?
http://archives.postgresql.org
From pgsql-hackers-owner+M18827=candle.pha.pa.us=pgman@postgresql.org Thu Feb 14 13:53:52 2002
Return-path: <pgsql-hackers-owner+M18827=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1EIrpP17729
for <pgman@candle.pha.pa.us>; Thu, 14 Feb 2002 13:53:51 -0500 (EST)
Received: (qmail 47648 invoked by alias); 14 Feb 2002 18:53:50 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 18:53:50 -0000
Received: from klamath.dyndns.org (CPE002078144ae0.cpe.net.cable.rogers.com [24.102.202.35])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1EIbiE46318
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 13:37:44 -0500 (EST)
(envelope-from nconway@klamath.dyndns.org)
Received: by klamath.dyndns.org (Postfix, from userid 1000)
id 032E8700C; Thu, 14 Feb 2002 13:37:44 -0500 (EST)
Date: Thu, 14 Feb 2002 13:37:43 -0500
To: pgsql-hackers@postgresql.org
Subject: Re: [HACKERS] NAMEDATALEN Changes
Message-ID: <20020214183743.GA10423@klamath.dyndns.org>
Mail-Followup-To: pgsql-hackers@postgresql.org
References: <Pine.LNX.4.30.0202131912010.683-100000@peter.localdomain> <4413.1013648406@sss.pgh.pa.us> <1013666380.5380.19.camel@jiro>
MIME-Version: 1.0
Content-Type: multipart/mixed; boundary="huq684BweRXVnRxX"
Content-Disposition: inline
In-Reply-To: <1013666380.5380.19.camel@jiro>
User-Agent: Mutt/1.3.27i
From: nconway@klamath.dyndns.org (Neil Conway)
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
--huq684BweRXVnRxX
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
On Thu, Feb 14, 2002 at 12:59:40AM -0500, Neil Conway wrote:
> I've attached a pretty trivial patch that implements this. Instead of
> automatically hashing NAMEDATALEN bytes, hashname() uses only strlen()
> bytes: this should improve both the common case (small identifers, 5-10
> characters long), as well as reduce the penalty when NAMEDATALEN is
> increased. The patch passes the regression tests, FWIW. I didn't remove
> cc_hashname() -- I'll tackle that tomorrow unless anyone objects...
Okay, I've attached a new version that removes cc_hashname(). As with
the previous patch, this passes the regression tests. Feedback is welcome.
Cheers,
Neil
--huq684BweRXVnRxX
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment; filename="hash_len.patch"
*** ./src/backend/access/hash/hashfunc.c.orig Wed Feb 13 21:09:37 2002
--- ./src/backend/access/hash/hashfunc.c Thu Feb 14 00:39:42 2002
***************
*** 95,101 ****
{
char *key = NameStr(*PG_GETARG_NAME(0));
! return hash_any((char *) key, NAMEDATALEN);
}
/*
--- 95,101 ----
{
char *key = NameStr(*PG_GETARG_NAME(0));
! return hash_any(key, strlen(key));
}
/*
***************
*** 125,131 ****
*
* (Comment from the original db3 hashing code: )
*
! * "This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
* units. On the first time through the loop we get the 'leftover bytes'
* (strlen % 8). On every later iteration, we perform 8 HASHC's so we handle
* all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. If
--- 125,131 ----
*
* (Comment from the original db3 hashing code: )
*
! * This is INCREDIBLY ugly, but fast. We break the string up into 8 byte
* units. On the first time through the loop we get the 'leftover bytes'
* (strlen % 8). On every later iteration, we perform 8 HASHC's so we handle
* all 8 bytes. Essentially, this saves us 7 cmp & branch instructions. If
***************
*** 134,140 ****
* "OZ's original sdbm hash"
*/
Datum
! hash_any(char *keydata, int keylen)
{
uint32 n;
int loop;
--- 134,140 ----
* "OZ's original sdbm hash"
*/
Datum
! hash_any(const char *keydata, int keylen)
{
uint32 n;
int loop;
*** ./src/backend/utils/cache/catcache.c.orig Thu Feb 14 12:51:00 2002
--- ./src/backend/utils/cache/catcache.c Thu Feb 14 12:53:05 2002
***************
*** 93,99 ****
static Index CatalogCacheComputeTupleHashIndex(CatCache *cache,
HeapTuple tuple);
static void CatalogCacheInitializeCache(CatCache *cache);
- static Datum cc_hashname(PG_FUNCTION_ARGS);
/*
--- 93,98 ----
***************
*** 109,115 ****
case CHAROID:
return hashchar;
case NAMEOID:
! return cc_hashname;
case INT2OID:
return hashint2;
case INT2VECTOROID:
--- 108,114 ----
case CHAROID:
return hashchar;
case NAMEOID:
! return hashname;
case INT2OID:
return hashint2;
case INT2VECTOROID:
***************
*** 129,151 ****
return (PGFunction) NULL;
}
}
-
- static Datum
- cc_hashname(PG_FUNCTION_ARGS)
- {
- /*
- * We need our own variant of hashname because we want to accept
- * null-terminated C strings as search values for name fields. So, we
- * have to make sure the data is correctly padded before we compute
- * the hash value.
- */
- NameData my_n;
-
- namestrcpy(&my_n, NameStr(*PG_GETARG_NAME(0)));
-
- return DirectFunctionCall1(hashname, NameGetDatum(&my_n));
- }
-
/*
* Standard routine for creating cache context if it doesn't exist yet
--- 128,133 ----
*** ./src/include/access/hash.h.orig Wed Feb 13 22:43:06 2002
--- ./src/include/access/hash.h Thu Feb 14 00:38:35 2002
***************
*** 265,271 ****
extern Datum hashint2vector(PG_FUNCTION_ARGS);
extern Datum hashname(PG_FUNCTION_ARGS);
extern Datum hashvarlena(PG_FUNCTION_ARGS);
! extern Datum hash_any(char *keydata, int keylen);
/* private routines */
--- 265,271 ----
extern Datum hashint2vector(PG_FUNCTION_ARGS);
extern Datum hashname(PG_FUNCTION_ARGS);
extern Datum hashvarlena(PG_FUNCTION_ARGS);
! extern Datum hash_any(const char *keydata, int keylen);
/* private routines */
--huq684BweRXVnRxX
Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly
--huq684BweRXVnRxX--
From pgsql-hackers-owner+M18833=candle.pha.pa.us=pgman@postgresql.org Thu Feb 14 16:22:34 2002
Return-path: <pgsql-hackers-owner+M18833=candle.pha.pa.us=pgman@postgresql.org>
Received: from server1.pgsql.org (www.postgresql.org [64.49.215.9])
by candle.pha.pa.us (8.11.6/8.10.1) with SMTP id g1ELMXP07956
for <pgman@candle.pha.pa.us>; Thu, 14 Feb 2002 16:22:34 -0500 (EST)
Received: (qmail 80517 invoked by alias); 14 Feb 2002 21:22:29 -0000
Received: from unknown (HELO postgresql.org) (64.49.215.8)
by www.postgresql.org with SMTP; 14 Feb 2002 21:22:29 -0000
Received: from post.webmailer.de (natpost.webmailer.de [192.67.198.65])
by postgresql.org (8.11.3/8.11.4) with ESMTP id g1EL2mE77720
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 16:02:48 -0500 (EST)
(envelope-from barwick@gmx.net)
Received: from there (pD9EB17D4.dip.t-dialin.net [217.235.23.212])
by post.webmailer.de (8.9.3/8.8.7) with SMTP id WAA07320
for <pgsql-hackers@postgresql.org>; Thu, 14 Feb 2002 22:02:49 +0100 (MET)
Message-ID: <200202142102.WAA07320@post.webmailer.de>
Content-Type: text/plain;
charset="iso-2022-jp"
From: Ian Barwick <barwick@gmx.net>
To: "Hackers List" <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] NAMEDATALEN Changes
Date: Thu, 14 Feb 2002 22:02:34 +0100
X-Mailer: KMail [version 1.3.1]
References: <003901c1b4ca$1d762500$8001a8c0@jester> <200202132227.XAA22201@post.webmailer.de>
In-Reply-To: <200202132227.XAA22201@post.webmailer.de>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk
Sender: pgsql-hackers-owner@postgresql.org
Status: OR
On Wednesday 13 February 2002 23:27, Ian Barwick wrote:
> On Wednesday 13 February 2002 21:07, Rod Taylor wrote:
> > NAMEDATALEN's benchmarked are 32, 64, 128 and 512. Attached is the
> > shell script I used to do it.
>
> Attached is a modified version for Linux, if anyone is interested.
>
> Will run it overnight out of quasi-scientific interest.
>
> Nice to have an idea what kind of effect my very long NAMEDATALEN setting
> (128) has.
Below the probably quite uninformative results, run under Linux with 2.2.16
on an AMD K2 350Mhz with 256MB RAM, EIDE HDs and other run of the mill
hardware.
I suspect some of the normal system jobs which usually run during the night
caused the wildly varying results. Whatever else, for my purposes at least
any performance issues with differening NAMEDATALENgths are nothing much
to worry about.
NAMEDATALEN: 32
220.73 real 3.39 user 0.10 sys
110.03 real 2.77 user 4.42 sys
NAMEDATALEN: 64
205.31 real 3.55 user 0.08 sys
109.76 real 2.53 user 4.18 sys
NAMEDATALEN: 128
224.65 real 3.35 user 0.10 sys
121.30 real 2.60 user 3.89 sys
NAMEDATALEN: 256
209.48 real 3.62 user 0.11 sys
118.90 real 3.00 user 3.88 sys
NAMEDATALEN: 512
204.65 real 3.36 user 0.14 sys
115.12 real 2.54 user 3.88 sys
Ian Barwick
---------------------------(end of broadcast)---------------------------
TIP 3: if posting/reading through Usenet, please send an appropriate
subscribe-nomail command to majordomo@postgresql.org so that your
message can get through to the mailing list cleanly
Reference in New Issue Copy Permalink