fujii.y...@df.mitsubishielectric.co.jp писал 2023-09-28 07:40:
I'm not sure that I like this mechanics of adding sort group clauses -
it seems we do in core additional work, which is of use only for
one extension, but at least it seems to be working.
We cannot deparse the original sort group clauses and pathtarget
when performing partial aggreggate pushdown by any FDWs.
So I think the additional sort group clauses and pathtarget are
needed by any FDWs, not only postgres_fdw.
Hi.
It seems to me that *fdw postfixes don't clarify things, but just make
naming more ugly.
+ * Adding these Vars and PlaceHolderVars to PathTarget,
+ * FDW cannot deparse this by the original List of SortGroupClauses.
+ * So, before this adding process,
+ * setGroupClausePartial generates another Pathtarget and another
+ * List of SortGroupClauses for FDW.
It seems that something like:
/*
* Modified PathTarget cannot be used by FDW as-is to deparse this
statement.
* So, before modifying PathTarget, setGroupClausePartial generates
* another Pathtarget and another list List of SortGroupClauses
* to make deparsing possible.
*/
sounds better.
--
Best regards,
Alexander Pyhalov,
Postgres Professional
