Re: BitmapHeapScan streaming read user and prelim refactoring - Mailing list pgsql-hackers

From Robert Haas
Subject Re: BitmapHeapScan streaming read user and prelim refactoring
Date
Msg-id CA+TgmoYiYQLSyj_-yjrtAkUTt+2i-k_NUek+tpr37EzAGXKO3A@mail.gmail.com
Whole thread Raw
In response to Re: BitmapHeapScan streaming read user and prelim refactoring  (Heikki Linnakangas <hlinnaka@iki.fi>)
Responses Re: BitmapHeapScan streaming read user and prelim refactoring
List pgsql-hackers
On Thu, Mar 14, 2024 at 6:37 AM Heikki Linnakangas <hlinnaka@iki.fi> wrote:
> If es_snapshot was different from the active snapshot, things would get
> weird, even without parallel query. The scans would use es_snapshot for
> the visibility checks, but any functions you execute in quals would use
> the active snapshot.

Hmm, that's an interesting point.

The case where the query is suspended and resumed - i.e. cursors are
used - probably needs more analysis. In that case, perhaps there's
more room for the snapshots to diverge.

--
Robert Haas
EDB: http://www.enterprisedb.com



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