Subject: Postgres 4.2 Problems...

From: [email-masked]
Date: Thu, 18 Aug 1994 10:13:38 -0600

Hello there,

We have five small Postgres databases against which we pose "randomly"
generated queries nightly.  Under SunOS 4.1.1 and Postgres version
4.0.1 we were able to pose greater than 10,000 queries without any
Postgres problems.  Now under Solaris 2.3 and Postgres 4.2 we are only
able to get about 3,000 before the ~postgres/data/pg_log file
(relation) balloons to 134 MB (the file is *extremely* sparse) and we
get the error:

WARN:Aug 15 10:17:08:cannot open segment 1 of relation pg_time

At this point we are not able to do any more with Postgres and our
homegrown solution is to use ~postgres/bin/cleardbdir,
~postgres/bin/initdb, and rebuild the five small databases.

As an experiment, we have also built Postgres 4.2 under SunOS 4.1.1.
Different problem here (the Postgres backend dies), but we are still
unable to get through as many queries as we were able to under version
4.0.1 of Postgres.  In fact, the number of queries we are able to
process is similar to the number processed under Solaris 2.3.

Both versions passed the regression test when I built them.  Has
anyone else experienced problems similar to this? 

       Sean Dalby
       Department of Mechanical Engineering Design Systems Laboratory
       University of Utah
       [email-masked]

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---

From: [email-masked] (Paul M. Aoki)
Date: Fri, 19 Aug 94 12:43:19 -0700

[email-masked] writes:
> (relation) balloons to 134 MB (the file is *extremely* sparse) 

last night i ran 20000 insert/update/select statements against
one table on solaris 2.3 and sunos 4.1.3.  the log/time tables 
were exactly the size you would expect from 20000 committed 
transactions (one bit per xact in log, four bytes per xact in 
time, allocated in 8k pages):

bohemia:aoki (12)> ls -l $PGDATA/pg_{log,time}
-rw-------   1 postgres postgres    8192 Aug 19 06:27 /tmp/data/pg_log
-rw-------   1 postgres postgres   90112 Aug 19 06:27 /tmp/data/pg_time
bohemia:aoki (13)> uname -a
SunOS bohemia.cs.berkeley.edu 5.3 Generic sun4m sparc

i just unpacked the binary distribution (which uses gcc) and 
used that.  our solaris compiler license expired again so i 
can't check that.

a sparse log file would normally suggest a lot of aborts, but it
seems hard to believe that postgres could even manage to *parse*
8 * 134,000,000 queries overnight, so i have no idea what might
be causing what you're seeing.. all i can say is, try the binary
distribution (if you aren't already) and see what happens.
--
  Paul M. Aoki          |  University of California at Berkeley
  [email-masked]  |  Dept. of EECS, Computer Science Division (#1776) 
                        |  Berkeley, CA 94720-1776