mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Oops, missed one fix for EquivalenceClass rearrangement.

Browse Source 
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.)
This commit is contained in:
Tom Lane 2010-10-29 14:44:49 -04:00
parent 14231a41a9
commit 48a1fb2390
1 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
src/backend/optimizer/prep/prepunion.c
View File

@ -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;