pgsql-bugs(at)postgresql(dot)org writes:
> Big diffrence in performence between 7.1 and 7.2.1. In 7.2.1 postmaster grows up to 700 MB RAM and more while in 7.1 just up to 8 MB RAM.
You have not given nearly enough information to allow any useful
response to this complaint.
For starters, what are the schemas of the tables involved? Have you
done ANALYZE (resp. VACUUM ANALYZE) recently? What do you get from
EXPLAIN for the problem query on both systems?
regards, tom lane