On 2/17/07,
elein <
elein@varlena.com> wrote:
I am sure this topic has probably been beaten to death in the past, but has anyone talked about the advantages of Oracle's MVCC model versus PostgreSQL's MVCC model? Oracle achieves multiversioning by using rollback/undo segments, where PostgreSQL appears to place (essentially) the undo in the same space as the table.
If I were to guess this is probably a major thing to change. Clearly there are advantages to both, with Oracle essentially the space consumed by a modified row is immediately available for reuse and generally there is little row migration assuming there is enough space on the block so you should be able to avoid updates to the index and the bloating that seems to go along with vacuuming.
Is there any previous discussions that folks could point out here?