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Don't pass down nonnullable_vars while reducing outer joins.

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We weren't actually using the passed-down list for anything, other
than computing the new value to be passed down further.  I (tgl)
probably had the idea that we'd need this data eventually; but
no use-case has emerged in a good long while, so let's just stop
expending useless cycles here.

Richard Guo

Discussion: https://postgr.es/m/CAMbWs48KLy9aBb=sZ5MoNmnqAcGHaW_JTGWLCgoE_uMW7S6C-A@mail.gmail.com
pull/108/head
Tom Lane 3 years ago
parent ff8fa0bf7e
commit b0b72c64a0
1 changed files with 6 additions and 27 deletions
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
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  1. 33
      src/backend/optimizer/prep/prepjointree.c

33
src/backend/optimizer/prep/prepjointree.c
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@ -117,7 +117,6 @@ static void reduce_outer_joins_pass2(Node *jtnode,
reduce_outer_joins_state *state,
PlannerInfo *root,
Relids nonnullable_rels,
List *nonnullable_vars,
List *forced_null_vars);
static Node *remove_useless_results_recurse(PlannerInfo *root, Node *jtnode);
static int get_result_relid(PlannerInfo *root, Node *jtnode);
@ -2693,7 +2692,7 @@ reduce_outer_joins(PlannerInfo *root)
elog(ERROR, "so where are the outer joins?");
reduce_outer_joins_pass2((Node *) root->parse->jointree,
state, root, NULL, NIL, NIL);
state, root, NULL, NIL);
}
/*
@ -2770,7 +2769,6 @@ reduce_outer_joins_pass1(Node *jtnode)
* state: state data collected by phase 1 for this node
* root: toplevel planner state
* nonnullable_rels: set of base relids forced non-null by upper quals
* nonnullable_vars: list of Vars forced non-null by upper quals
* forced_null_vars: list of Vars forced null by upper quals
*/
static void
@ -2778,7 +2776,6 @@ reduce_outer_joins_pass2(Node *jtnode,
reduce_outer_joins_state *state,
PlannerInfo *root,
Relids nonnullable_rels,
List *nonnullable_vars,
List *forced_null_vars)
{
/*
@ -2795,16 +2792,12 @@ reduce_outer_joins_pass2(Node *jtnode,
ListCell *l;
ListCell *s;
Relids pass_nonnullable_rels;
List *pass_nonnullable_vars;
List *pass_forced_null_vars;
/* Scan quals to see if we can add any constraints */
pass_nonnullable_rels = find_nonnullable_rels(f->quals);
pass_nonnullable_rels = bms_add_members(pass_nonnullable_rels,
nonnullable_rels);
pass_nonnullable_vars = find_nonnullable_vars(f->quals);
pass_nonnullable_vars = list_concat(pass_nonnullable_vars,
nonnullable_vars);
pass_forced_null_vars = find_forced_null_vars(f->quals);
pass_forced_null_vars = list_concat(pass_forced_null_vars,
forced_null_vars);
@ -2817,7 +2810,6 @@ reduce_outer_joins_pass2(Node *jtnode,
if (sub_state->contains_outer)
reduce_outer_joins_pass2(lfirst(l), sub_state, root,
pass_nonnullable_rels,
pass_nonnullable_vars,
pass_forced_null_vars);
}
bms_free(pass_nonnullable_rels);
@ -2830,8 +2822,6 @@ reduce_outer_joins_pass2(Node *jtnode,
JoinType jointype = j->jointype;
reduce_outer_joins_state *left_state = linitial(state->sub_states);
reduce_outer_joins_state *right_state = lsecond(state->sub_states);
List *local_nonnullable_vars = NIL;
bool computed_local_nonnullable_vars = false;
/* Can we simplify this join? */
switch (jointype)
@ -2906,17 +2896,18 @@ reduce_outer_joins_pass2(Node *jtnode,
*/
if (jointype == JOIN_LEFT)
{
List *nonnullable_vars;
List *overlap;
local_nonnullable_vars = find_nonnullable_vars(j->quals);
computed_local_nonnullable_vars = true;
/* Find Vars in j->quals that must be non-null in joined rows */
nonnullable_vars = find_nonnullable_vars(j->quals);
/*
* It's not sufficient to check whether local_nonnullable_vars and
* It's not sufficient to check whether nonnullable_vars and
* forced_null_vars overlap: we need to know if the overlap
* includes any RHS variables.
*/
overlap = list_intersection(local_nonnullable_vars,
overlap = list_intersection(nonnullable_vars,
forced_null_vars);
if (overlap != NIL &&
bms_overlap(pull_varnos(root, (Node *) overlap),
@ -2941,7 +2932,6 @@ reduce_outer_joins_pass2(Node *jtnode,
Relids local_nonnullable_rels;
List *local_forced_null_vars;
Relids pass_nonnullable_rels;
List *pass_nonnullable_vars;
List *pass_forced_null_vars;
/*
@ -2968,16 +2958,12 @@ reduce_outer_joins_pass2(Node *jtnode,
if (jointype != JOIN_FULL)
{
local_nonnullable_rels = find_nonnullable_rels(j->quals);
if (!computed_local_nonnullable_vars)
local_nonnullable_vars = find_nonnullable_vars(j->quals);
local_forced_null_vars = find_forced_null_vars(j->quals);
if (jointype == JOIN_INNER || jointype == JOIN_SEMI)
{
/* OK to merge upper and local constraints */
local_nonnullable_rels = bms_add_members(local_nonnullable_rels,
nonnullable_rels);
local_nonnullable_vars = list_concat(local_nonnullable_vars,
nonnullable_vars);
local_forced_null_vars = list_concat(local_forced_null_vars,
forced_null_vars);
}
@ -2995,26 +2981,22 @@ reduce_outer_joins_pass2(Node *jtnode,
{
/* pass union of local and upper constraints */
pass_nonnullable_rels = local_nonnullable_rels;
pass_nonnullable_vars = local_nonnullable_vars;
pass_forced_null_vars = local_forced_null_vars;
}
else if (jointype != JOIN_FULL) /* ie, LEFT or ANTI */
{
/* can't pass local constraints to non-nullable side */
pass_nonnullable_rels = nonnullable_rels;
pass_nonnullable_vars = nonnullable_vars;
pass_forced_null_vars = forced_null_vars;
}
else
{
/* no constraints pass through JOIN_FULL */
pass_nonnullable_rels = NULL;
pass_nonnullable_vars = NIL;
pass_forced_null_vars = NIL;
}
reduce_outer_joins_pass2(j->larg, left_state, root,
pass_nonnullable_rels,
pass_nonnullable_vars,
pass_forced_null_vars);
}
@ -3024,19 +3006,16 @@ reduce_outer_joins_pass2(Node *jtnode,
{
/* pass appropriate constraints, per comment above */
pass_nonnullable_rels = local_nonnullable_rels;
pass_nonnullable_vars = local_nonnullable_vars;
pass_forced_null_vars = local_forced_null_vars;
}
else
{
/* no constraints pass through JOIN_FULL */
pass_nonnullable_rels = NULL;
pass_nonnullable_vars = NIL;
pass_forced_null_vars = NIL;
}
reduce_outer_joins_pass2(j->rarg, right_state, root,
pass_nonnullable_rels,
pass_nonnullable_vars,
pass_forced_null_vars);
}
bms_free(local_nonnullable_rels);

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