Re: VACUUM/t_ctid bug (was Re: GiST concurrency commited)

> http://archives.postgresql.org/pgsql-patches/2005-08/msg00304.php
>
> Could you perhaps test this patch as well, while you already have a
> setup for testing parallel vacuums under big loads ?

Ok, I'll do it.

>
> Or perhaps you can share the setup/scripts/data so that I could run your
> test myself as well ?
>
Statements generator:
http://www.sigaev.ru/gist/concur.pl
Usage:
./concur.pl -d DATABASE [-n N] [-c N] [-l]
-d DATABASE - DATABASE name
-n N - number of rows
-c N - number of flow
-l - linear mode

Script guarantees the same result (ie the same data in table) with the same -n
and -c options, result doesn't depend on -l option. Also script guarantees
absence of dead locks.

% perl concur.pl -d qq -n 100000 -c 4
Start: parallel mode with 4 flows
3 flow finish. Stats: ni:25000 nu:555 nd:81 nv:4(nf:1) nt:232
0 flow finish. Stats: ni:25000 nu:554 nd:77 nv:2(nf:0) nt:247
1 flow finish. Stats: ni:25000 nu:548 nd:65 nv:4(nf:1) nt:249
2 flow finish. Stats: ni:25000 nu:552 nd:79 nv:7(nf:2) nt:263
All flow finish; status: 0; elapsed time: 159.25 sec

Script prints some statistics per flow:
ni - number of insert's statements (sum of this should be equal to -n N)
nu - -/- update's statements
nd - -/- delete's statements
nv - -/- vacuum (including full vacuum)
nf - number of full vacuum
nt - number of transactions

Simple wrapper for manipulating test table and loop testing (you should edit it
to right paths):
http://www.sigaev.ru/gist/concur.sh

Those scripts was wrote to test GiST concurrency.

I suspect it's needed to make some changes in generator to increase number of
updates and vacuums for your goal.

--
Teodor Sigaev E-mail: teodor(at)sigaev(dot)ru
WWW: http://www.sigaev.ru/