[PERFORM] How can an index be larger than a table

Hi, I have a series of tables with identical structure. Some contain a few thousand rows and some contain 3,000,000 rows. Another applicate writes the rows and my applicate reads then just by selecting where pk last_seen_pk limit 2000. I've found that one of the tables, when selecting from it

Re: [PERFORM] How can an index be larger than a table

David, What also seems weird to me is that the control table has some unique indexes created on it, but the data_upate_events table just has a unique constraint.  Will postgres use an index in the background to enforce this constraint? If you somehow have a unique constraint without a unique