Tom Lane wrote:
>
> Hiroshi Inoue <Inoue@tpf.co.jp> writes:
> > Currently PostgreSQL ignores the update/deleted
> > tuples from the first which don't satisfy the
> > qualification at the point of snapshot.
>
> It does? It looks to me like we use SnapshotDirty time qual check
> and wait for any uncommitted transaction. This essentially means
> that we use "latest committed" state, not the query-start snapshot.
I don't refer to SnapshotDirty(Now/Self/Any) as the snapshot
because they aren't real snapshots.
What I meant is e.g.
update t set .. = .. where ...;
PostgreSQL ignores the tuples which don't satisfy the
where clause at the point when the query started(or
when the transaction started in serializable mode)
even though it happend to look already update/delete
(/insert)ed tuples.
regards,
Hiroshi Inoue