database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-19 13:42:17 +03:00
Code Activity

Invent "join domains" to replace the below_outer_join hack.

Browse Source 
EquivalenceClasses are now understood as applying within a "join
domain", which is a set of inner-joined relations (possibly underneath
an outer join).  We no longer need to treat an EC from below an outer
join as a second-class citizen.

I have hopes of eventually being able to treat outer-join clauses via
EquivalenceClasses, by means of only applying deductions within the
EC's join domain.  There are still problems in the way of that, though,
so for now the reconsider_outer_join_clause logic is still here.

I haven't been able to get rid of RestrictInfo.is_pushed_down either,
but I wonder if that could be recast using JoinDomains.

I had to hack one test case in postgres_fdw.sql to make it still test
what it was meant to, because postgres_fdw is inconsistent about
how it deals with quals containing non-shippable expressions; see
https://postgr.es/m/1691374.1671659838@sss.pgh.pa.us.  That should
be improved, but I don't think it's within the scope of this patch
series.

Patch by me; thanks to Richard Guo for review.

Discussion: https://postgr.es/m/830269.1656693747@sss.pgh.pa.us
This commit is contained in:
Tom Lane
2023-01-30 13:50:25 -05:00
parent b448f1c8d8
commit 3bef56e116
12 changed files with 269 additions and 193 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
src/backend/optimizer/prep/prepjointree.c
View File

@@ -991,6 +991,7 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
subroot->init_plans = NIL;
subroot->cte_plan_ids = NIL;
subroot->multiexpr_params = NIL;
subroot->join_domains = NIL;
subroot->eq_classes = NIL;
subroot->ec_merging_done = false;
subroot->last_rinfo_serial = 0;
@@ -1012,6 +1013,7 @@ pull_up_simple_subquery(PlannerInfo *root, Node *jtnode, RangeTblEntry *rte,
subroot->hasRecursion = false;
subroot->wt_param_id = -1;
subroot->non_recursive_path = NULL;
/* We don't currently need a top JoinDomain for the subroot */
/* No CTEs to worry about */
Assert(subquery->cteList == NIL);