Jeff <threshar(at)torgo(dot)978(dot)org> writes:
> [ pg_clog not getting truncated ]
pg_clog is truncated on the basis of the oldest completely vacuumed
database in your installation. Most likely your maintenance script
is failing to vacuum some database(s) (template1, perhaps?) and/or
is doing table-by-table vacuums rather than an unqualified VACUUM.
I doubt this explains any performance problems though. Old pg_clog
segments don't do anything except sit there.
regards, tom lane