Postgres

Dear Sir
,
My company is www.annotate.net and we are using postgresql to implement a large database. I'm hoping your expertise with postgresql can shed some light on a problem that we are having.
We have several postgres databases running under Linux with a high grade duel Pentium machine. The largest database that we have has a table that consists of 80,000 records. Recently this database was corrupted when the disk ran out of space. After freeing up a large amount of disk space we were able to restore the database from a previous pg_dump. shortly after being restored I did a update on a non indexed field of all 80,000 records where I changed the value of a fields integer. This update never finishes. I have tried several times and have left it run for over 12 hours without ever completing the query. the postmaster continues to run and take up memory but doesn't finish. any suggestions on what this might be and how to remedy it would be appreciated? Also assuming that we can remedy this problem, how big can we grow a postges db? we need it to hold over 1,000,000 in a single table.

Thank you for your help,
Matthew Schwartz