Actually, PostgreSQL's MVCC architecture makes lock contention radically less likely than with most other DBMSes. For SELECTs, you're only ever taking "Access S

Actually, PostgreSQL's MVCC architecture makes lock contention radically less likely than with most other DBMSes. For SELECTs, you're only ever taking "Access Share" locks on the table ("Hey, I'm using this table; you can't DROP it right now."). For DML queries (UPDATE, INSERT, DELETE), you'll see those, plus "Row Exclusive", which is just what it sounds like. There are a few other lock types you'll run into as well, but they're typically only seen in narrow, specific cases -- when you're performing maintenance (vacuuming, clustering, &c), indexing, DDL changes, or when you explicitly LOCK a table for whatever reason.