> How is PGSQL Locking compared with Oracle's MVCC? How PGSQL handles > concurreny and how it differs with Oracle's Multi-Version Concurrency > Control (MVCC)? In PostgreSQL, old rows remain in the table until the table is vacuumed. In Oracle, old rows are kept in the 'undo table space' until - well, until the undo table space runs out and they are recycled. Depends. I have never heard this referred to as 'MVCC'. Locking and concurrency work pretty similar in both - at least as far as the behaviour is concerned. Yours, Laurenz Albe
