Re: Removal of currtid()/currtid2() and some table AM cleanup

On Tue, Jun 23, 2020 at 02:02:33PM +0900, Michael Paquier wrote:
> Actually, while reviewing the code, the only code path where we use
> currtid2() involves positioned_load() and LATEST_TUPLE_LOAD.  And the
> only location where this happens is in SC_pos_reload_with_key(), where
> I don't actually see how it would be possible to not have a keyset and
> still use a CTID, which would led to LATEST_TUPLE_LOAD being used.  So
> could it be possible that the code paths of currtid2() are actually
> just dead code?

I have dug more into this one, and we actually stressed this code path
quite a lot up to commit d9cb23f in the ODBC driver, with tests
cursor-block-delete, positioned-update and bulkoperations particularly
when calling SQLSetPos().  However, 86e2e7a has reworked the code in
such a way that we visibly don't use anymore CTIDs if we don't have a
keyset, and that combinations of various options like UseDeclareFetch
or UpdatableCursors don't trigger this code path anymore.  In short,
currtid2() does not get used.  Inoue-san, Saito-san, what do you
think?  I am adding also Tsunakawa-san in CC who has some experience
in this area.
--
Michael