On 2017/03/29 15:20, Ashutosh Bapat wrote: > The prologue of set_append_rel_size() mentions > > * .... Note that in the inheritance case, > * the first member relation is actually the same table as is mentioned in > * the parent RTE ... but it has a different RTE and RelOptInfo. > > This isn't true about partitioned tables anymore. We do not create > RelOptInfo of the partitioned table and thus is not first member > relation.
My bad. > We could argue that inheritance in case of partitioned > tables is just an implementation detail and partitioned table is not > "inherited" in true sense. So "inheritance case" referred to here does > not cover partitioning and so the sentence still holds. But I guess, > this needs some change so that we do not expect first member to be > same as partitioned table. I am not able to craft an elegant sentence > but how about something like attached? I think we *should* update the comment somwhow. Since now there are a few places using "non-partitioned inheritance" to refer to regular parent tables, why not use that term here too? So: * The passed-in rel and RTE represent the entire append relation. The - * relation's contents are computed by appending together the output of - * the individual member relations. Note that in the inheritance case, - * the first member relation is actually the same table as is mentioned in - * the parent RTE ... but it has a different RTE and RelOptInfo. This is + * relation's contents are computed by appending together the output of the + * individual member relations. Note that in the non-partitioned inheritance + * case, the first member relation is actually the same table as is mentioned + * in the parent RTE ... but it has a different RTE and RelOptInfo. This is Update patch attached. Thanks, Amit
diff --git a/src/backend/optimizer/path/allpaths.c b/src/backend/optimizer/path/allpaths.c index a1e1a87c29..9fce9437f8 100644 --- a/src/backend/optimizer/path/allpaths.c +++ b/src/backend/optimizer/path/allpaths.c @@ -834,10 +834,10 @@ set_foreign_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte) * Set size estimates for an "append relation" * * The passed-in rel and RTE represent the entire append relation. The - * relation's contents are computed by appending together the output of - * the individual member relations. Note that in the inheritance case, - * the first member relation is actually the same table as is mentioned in - * the parent RTE ... but it has a different RTE and RelOptInfo. This is + * relation's contents are computed by appending together the output of the + * individual member relations. Note that in the non-partitioned inheritance + * case, the first member relation is actually the same table as is mentioned + * in the parent RTE ... but it has a different RTE and RelOptInfo. This is * a good thing because their outputs are not the same size. */ static void
-- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
