Thread: Postgresql 7.1.3 not thread safe

Postgresql 7.1.3 not thread safe

From
Alain Picard
Date:
>>>>> In article <15473.43974.509236.142554@localhost.localdomain>, Alain Picard <alain.picard@memetrics.com> writes:

ap> This contrived example is the simplest form I can reproduce the
ap> problem to.  My actual application is written in lisp, and uses
ap> unixODBC to talk to postgresql, though I believe the above problem
ap> should be reproducible using any client.  I might write a perl
ap> script using the DBD stuff to test this.  If I can reproduce the
ap> problem there, I'll forward the script.

I've included such a script, and it does reproduce the problem.
Run it as follows

1) create the table as per the previous message
2) run two copies of the scripts CONCURRENTLY.
% ./bang.pl 20000 a 2000000 &
% ./bang.pl 20000 b 2000000 &
3) When both scripts have finished, run the query

select * from test_table
where data
!='bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb'
and
data !=
'aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa';

in psql, which should return no records in postgres is working OK.


You may have to run with a higher number of hits,
or with more concurrent processes, to increase your chances
of failure, especially on slow machines.


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