There have been a number of changes to PostgreSQL over the last few versions which have required work on the OpenACS to accommodate.
Not all versions of OpenACS support all PostgreSQL versions (check out the version compatibility matrix
here)
There are also quite extensive posts on the forum discussing upgrade issues, the most recent of which centred around changes to the way PostgreSQL represents/returns time stamps. There have also been issues with the backup and restore program pg_dump in previous versions of PostgreSQL not properly restoring certain function definitions.
This error appears to be related to a change in a data type in PostgreSQL which is breaking one of the queries in your openacs (others in this community will know immediately which change to PostgreSQL caused this and there is probably an upgrade doc somewhere on this site if you search for it).
The basic conclusion for you will I think be that it is too much work to try to single handedly fix all the upgrade bugs on your installation. So your options probably are:
1) Download the PostgreSQL 7.2.2 source code from http://www.postgresql.org and compile it to replace the version in RedHat8.0 (I install RedHat without Postgres and compile from source on my system). Very little work and avoids big changes to your existing site.
or..
2) Upgrade your site to OpenACS 4.6.3 (or even 5.0.4). This will still require you to compile a more recent version of Postgres (see the matrix). You might be able to upgrade to postgres 7.2.3 using the RedHat up-2-date program, but compiling Postgres is easy (just a couple of gotchas which are covered on the forum). This option may also be a lot of work because the upgrade to the new generation OpenACS might be painful.
I hope this helps.
Regards
Richard
