Re: Why does exec_simple_query requires 2 snapshots - Mailing list pgsql-hackers

From Tom Lane
Subject Re: Why does exec_simple_query requires 2 snapshots
Date
Msg-id 1241667.1739893420@sss.pgh.pa.us
Whole thread Raw
In response to Why does exec_simple_query requires 2 snapshots  (Andy Fan <zhihuifan1213@163.com>)
Responses Re: Why does exec_simple_query requires 2 snapshots
List pgsql-hackers
Andy Fan <zhihuifan1213@163.com> writes:
> My question is why can't we share the same snapshot for the 2 cases?
> parser & planner requires Catalog Snapshot which should be the 
> latest one, but in the above case, looks the executor can reuse it as
> well. Is there anything I missed?

Many years ago, we committed a patch to do exactly that.  We had
to back it out again because it broke too many real-world scenarios.
I'm too lazy to search the archives for you, but you might be able
to find the commit and revert by searching the git history.

            regards, tom lane



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