On 14/03/2024 12:55, Dilip Kumar wrote:
On Thu, Mar 14, 2024 at 4:07 PM Heikki Linnakangas <hlinn...@iki.fi> wrote:
_SPI_execute_plan() has code to deal with the possibility that the
active snapshot is not set. That seems fishy; do we really support SPI
without any snapshot? I'm inclined to turn that into an error. I ran the
regression tests with an "Assert(ActiveSnapshotSet())" there, and
everything worked.
IMHO, we can call SPI_Connect() and SPI_Execute() from any C
extension, so I don't think there we can guarantee that the snapshot
must be set, do we?
I suppose, although the things you could do without a snapshot would be
pretty limited. The query couldn't access any tables. Could it even look
up functions in the parser? Not sure.
Maybe for now we can just handle this specific case to remove the
snapshot serializing for the BitmapHeapScan as you are doing in the
patch. After looking into the code your theory seems correct that we
are just copying the ActiveSnapshot while building the query
descriptor and from there we are copying into the Estate so logically
there should not be any reason for these two to be different.
Ok, committed that for now. Thanks for looking!
--
Heikki Linnakangas
Neon (https://neon.tech)
