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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2010-10-29 14:44:49 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2010-10-29 14:44:49 -0400 |
| commit | 48a1fb23900d73e7d9cb2dc0408c745cd03597a7 (patch) | |
| tree | a454932e37a27dbfd9b2c38d5fd7c3a41908fd5b | |
| parent | 14231a41a94b2345cc679ff67dbee1bf7dac7029 (diff) | |
| download | postgresql-48a1fb23900d73e7d9cb2dc0408c745cd03597a7.tar.gz postgresql-48a1fb23900d73e7d9cb2dc0408c745cd03597a7.zip | |
Oops, missed one fix for EquivalenceClass rearrangement.
Now that we're expecting a mergeclause's left_ec/right_ec to persist from
the initial assignments, we can't just blithely zero these out when
transforming such a clause in adjust_appendrel_attrs. But really it should
be okay to keep the parent's values, since a child table's derived Var
ought to be equivalent to the parent Var for all EquivalenceClass purposes.
(Indeed, I'm wondering whether we couldn't find a way to dispense with
add_child_rel_equivalences altogether. But this is wrong in any case.)
| -rw-r--r-- | src/backend/optimizer/prep/prepunion.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/src/backend/optimizer/prep/prepunion.c b/src/backend/optimizer/prep/prepunion.c index 0d3a739175a..45ecde416f9 100644 --- a/src/backend/optimizer/prep/prepunion.c +++ b/src/backend/optimizer/prep/prepunion.c @@ -1682,13 +1682,13 @@ adjust_appendrel_attrs_mutator(Node *node, AppendRelInfo *context) /* * Reset cached derivative fields, since these might need to have - * different values when considering the child relation. + * different values when considering the child relation. Note we + * don't reset left_ec/right_ec: each child variable is implicitly + * equivalent to its parent, so still a member of the same EC if any. */ newinfo->eval_cost.startup = -1; newinfo->norm_selec = -1; newinfo->outer_selec = -1; - newinfo->left_ec = NULL; - newinfo->right_ec = NULL; newinfo->left_em = NULL; newinfo->right_em = NULL; newinfo->scansel_cache = NIL; |