I wrote:
> Back in bd3daddaf232d95b0c9ba6f99b0170a0147dd8af, which introduced
> AlternativeSubPlans, I wrote:
> There is a lot more that could be done based on this infrastructure: in
> particular it's interesting to consider switching to the hash plan if we
> start
> out using the non-hashed plan but find a lot more upper rows going by than
> we
> expected. I have therefore left some minor inefficiencies in place, such as
> initializing both subplans even though we will currently only use one.
>
> That commit will be twelve years old come August, and nobody has either
> built anything else atop it or shown any interest in making the plan choice
> switchable mid-run. So it seems like kind of a failed experiment.
>
> Therefore, I'm considering the idea of ripping out all executor support
> for AlternativeSubPlan and instead having the planner replace an
> AlternativeSubPlan with the desired specific SubPlan somewhere late in
> planning, possibly setrefs.c.
Here's a proposed patchset for that. This runs with the idea I'd had
that setrefs.c could be smarter than the executor about which plan node
subexpressions will be executed how many times. I did not take it very
far, for fear of adding an undue number of planning cycles, but it's still
better than what we have now.
For ease of review, 0001 adds the new planner logic, while 0002 removes
the now-dead executor support.
There's one bit of dead code that I left in place for the moment, which is
ruleutils.c's support for printing AlternativeSubPlans. I'm not sure if
that's worth keeping or not --- it's dead code for normal use, but if
someone tried to use ruleutils.c to print partially-planned expression
trees, maybe there'd be a use for it?
(It's also arguable that readfuncs.c's support is now dead code, but
I have little interest in stripping that out.)
regards, tom lane
diff --git a/src/backend/nodes/outfuncs.c b/src/backend/nodes/outfuncs.c
index e2f177515d..f0386480ab 100644
--- a/src/backend/nodes/outfuncs.c
+++ b/src/backend/nodes/outfuncs.c
@@ -2254,6 +2254,7 @@ _outPlannerInfo(StringInfo str, const PlannerInfo *node)
WRITE_BOOL_FIELD(hasLateralRTEs);
WRITE_BOOL_FIELD(hasHavingQual);
WRITE_BOOL_FIELD(hasPseudoConstantQuals);
+ WRITE_BOOL_FIELD(hasAlternativeSubPlans);
WRITE_BOOL_FIELD(hasRecursion);
WRITE_INT_FIELD(wt_param_id);
WRITE_BITMAPSET_FIELD(curOuterRels);
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c
index b40a112c25..27006c59e0 100644
--- a/src/backend/optimizer/plan/planner.c
+++ b/src/backend/optimizer/plan/planner.c
@@ -629,6 +629,8 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
root->minmax_aggs = NIL;
root->qual_security_level = 0;
root->inhTargetKind = INHKIND_NONE;
+ root->hasPseudoConstantQuals = false;
+ root->hasAlternativeSubPlans = false;
root->hasRecursion = hasRecursion;
if (hasRecursion)
root->wt_param_id = assign_special_exec_param(root);
@@ -759,9 +761,6 @@ subquery_planner(PlannerGlobal *glob, Query *parse,
*/
root->hasHavingQual = (parse->havingQual != NULL);
- /* Clear this flag; might get set in distribute_qual_to_rels */
- root->hasPseudoConstantQuals = false;
-
/*
* Do expression preprocessing on targetlist and quals, as well as other
* random expressions in the querytree. Note that we do not need to
diff --git a/src/backend/optimizer/plan/setrefs.c b/src/backend/optimizer/plan/setrefs.c
index baefe0e946..b5a29ecfc4 100644
--- a/src/backend/optimizer/plan/setrefs.c
+++ b/src/backend/optimizer/plan/setrefs.c
@@ -49,6 +49,7 @@ typedef struct
{
PlannerInfo *root;
int rtoffset;
+ double num_exec;
} fix_scan_expr_context;
typedef struct
@@ -58,6 +59,7 @@ typedef struct
indexed_tlist *inner_itlist;
Index acceptable_rel;
int rtoffset;
+ double num_exec;
} fix_join_expr_context;
typedef struct
@@ -66,8 +68,28 @@ typedef struct
indexed_tlist *subplan_itlist;
Index newvarno;
int rtoffset;
+ double num_exec;
} fix_upper_expr_context;
+/*
+ * Selecting the best alternative in an AlternativeSubPlan expression requires
+ * estimating how many times that expression will be evaluated. For an
+ * expression in a plan node's targetlist, the plan's estimated number of
+ * output rows is clearly what to use, but for an expression in a qual it's
+ * far less clear. Since AlternativeSubPlans aren't heavily used, we don't
+ * want to expend a lot of cycles making such estimates. What we use is twice
+ * the number of output rows. That's not entirely unfounded: we know that
+ * clause_selectivity() would fall back to a default selectivity estimate
+ * of 0.5 for any SubPlan, so if the qual containing the SubPlan is the last
+ * to be applied (which it likely would be, thanks to order_qual_clauses()),
+ * this matches what we could have estimated in a far more laborious fashion.
+ * Obviously there are many other scenarios, but it's probably not worth the
+ * trouble to try to improve on this estimate, especially not when we don't
+ * have a better estimate for the selectivity of the SubPlan qual itself.
+ */
+#define NUM_EXEC_TLIST(parentplan) ((parentplan)->plan_rows)
+#define NUM_EXEC_QUAL(parentplan) ((parentplan)->plan_rows * 2.0)
+
/*
* Check if a Const node is a regclass value. We accept plain OID too,
* since a regclass Const will get folded to that type if it's an argument
@@ -79,8 +101,8 @@ typedef struct
(((con)->consttype == REGCLASSOID || (con)->consttype == OIDOID) && \
!(con)->constisnull)
-#define fix_scan_list(root, lst, rtoffset) \
- ((List *) fix_scan_expr(root, (Node *) (lst), rtoffset))
+#define fix_scan_list(root, lst, rtoffset, num_exec) \
+ ((List *) fix_scan_expr(root, (Node *) (lst), rtoffset, num_exec))
static void add_rtes_to_flat_rtable(PlannerInfo *root, bool recursing);
static void flatten_unplanned_rtes(PlannerGlobal *glob, RangeTblEntry *rte);
@@ -109,7 +131,8 @@ static Plan *set_mergeappend_references(PlannerInfo *root,
int rtoffset);
static void set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset);
static Relids offset_relid_set(Relids relids, int rtoffset);
-static Node *fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset);
+static Node *fix_scan_expr(PlannerInfo *root, Node *node,
+ int rtoffset, double num_exec);
static Node *fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context);
static bool fix_scan_expr_walker(Node *node, fix_scan_expr_context *context);
static void set_join_references(PlannerInfo *root, Join *join, int rtoffset);
@@ -133,14 +156,15 @@ static List *fix_join_expr(PlannerInfo *root,
List *clauses,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
- Index acceptable_rel, int rtoffset);
+ Index acceptable_rel,
+ int rtoffset, double num_exec);
static Node *fix_join_expr_mutator(Node *node,
fix_join_expr_context *context);
static Node *fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
Index newvarno,
- int rtoffset);
+ int rtoffset, double num_exec);
static Node *fix_upper_expr_mutator(Node *node,
fix_upper_expr_context *context);
static List *set_returning_clause_references(PlannerInfo *root,
@@ -177,17 +201,20 @@ static List *set_returning_clause_references(PlannerInfo *root,
* 5. PARAM_MULTIEXPR Params are replaced by regular PARAM_EXEC Params,
* now that we have finished planning all MULTIEXPR subplans.
*
- * 6. We compute regproc OIDs for operators (ie, we look up the function
+ * 6. AlternativeSubPlan expressions are replaced by just one of their
+ * alternatives, using an estimate of how many times they'll be executed.
+ *
+ * 7. We compute regproc OIDs for operators (ie, we look up the function
* that implements each op).
*
- * 7. We create lists of specific objects that the plan depends on.
+ * 8. We create lists of specific objects that the plan depends on.
* This will be used by plancache.c to drive invalidation of cached plans.
* Relation dependencies are represented by OIDs, and everything else by
* PlanInvalItems (this distinction is motivated by the shared-inval APIs).
* Currently, relations, user-defined functions, and domains are the only
* types of objects that are explicitly tracked this way.
*
- * 8. We assign every plan node in the tree a unique ID.
+ * 9. We assign every plan node in the tree a unique ID.
*
* We also perform one final optimization step, which is to delete
* SubqueryScan, Append, and MergeAppend plan nodes that aren't doing
@@ -490,9 +517,11 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scanrelid += rtoffset;
splan->plan.targetlist =
- fix_scan_list(root, splan->plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->plan.qual =
- fix_scan_list(root, splan->plan.qual, rtoffset);
+ fix_scan_list(root, splan->plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_SampleScan:
@@ -501,11 +530,14 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->tablesample = (TableSampleClause *)
- fix_scan_expr(root, (Node *) splan->tablesample, rtoffset);
+ fix_scan_expr(root, (Node *) splan->tablesample,
+ rtoffset, 1);
}
break;
case T_IndexScan:
@@ -514,17 +546,23 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->indexqual =
- fix_scan_list(root, splan->indexqual, rtoffset);
+ fix_scan_list(root, splan->indexqual,
+ rtoffset, 1);
splan->indexqualorig =
- fix_scan_list(root, splan->indexqualorig, rtoffset);
+ fix_scan_list(root, splan->indexqualorig,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->indexorderby =
- fix_scan_list(root, splan->indexorderby, rtoffset);
+ fix_scan_list(root, splan->indexorderby,
+ rtoffset, 1);
splan->indexorderbyorig =
- fix_scan_list(root, splan->indexorderbyorig, rtoffset);
+ fix_scan_list(root, splan->indexorderbyorig,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_IndexOnlyScan:
@@ -543,9 +581,10 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
Assert(splan->scan.plan.targetlist == NIL);
Assert(splan->scan.plan.qual == NIL);
splan->indexqual =
- fix_scan_list(root, splan->indexqual, rtoffset);
+ fix_scan_list(root, splan->indexqual, rtoffset, 1);
splan->indexqualorig =
- fix_scan_list(root, splan->indexqualorig, rtoffset);
+ fix_scan_list(root, splan->indexqualorig,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_BitmapHeapScan:
@@ -554,11 +593,14 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->bitmapqualorig =
- fix_scan_list(root, splan->bitmapqualorig, rtoffset);
+ fix_scan_list(root, splan->bitmapqualorig,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_TidScan:
@@ -567,11 +609,14 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->tidquals =
- fix_scan_list(root, splan->tidquals, rtoffset);
+ fix_scan_list(root, splan->tidquals,
+ rtoffset, 1);
}
break;
case T_SubqueryScan:
@@ -585,11 +630,13 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->functions =
- fix_scan_list(root, splan->functions, rtoffset);
+ fix_scan_list(root, splan->functions, rtoffset, 1);
}
break;
case T_TableFuncScan:
@@ -598,11 +645,14 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->tablefunc = (TableFunc *)
- fix_scan_expr(root, (Node *) splan->tablefunc, rtoffset);
+ fix_scan_expr(root, (Node *) splan->tablefunc,
+ rtoffset, 1);
}
break;
case T_ValuesScan:
@@ -611,11 +661,14 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->values_lists =
- fix_scan_list(root, splan->values_lists, rtoffset);
+ fix_scan_list(root, splan->values_lists,
+ rtoffset, 1);
}
break;
case T_CteScan:
@@ -624,9 +677,11 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_NamedTuplestoreScan:
@@ -635,9 +690,11 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_WorkTableScan:
@@ -646,9 +703,11 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
splan->scan.scanrelid += rtoffset;
splan->scan.plan.targetlist =
- fix_scan_list(root, splan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->scan.plan.qual =
- fix_scan_list(root, splan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, splan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
break;
case T_ForeignScan:
@@ -732,9 +791,9 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
Assert(splan->plan.qual == NIL);
splan->limitOffset =
- fix_scan_expr(root, splan->limitOffset, rtoffset);
+ fix_scan_expr(root, splan->limitOffset, rtoffset, 1);
splan->limitCount =
- fix_scan_expr(root, splan->limitCount, rtoffset);
+ fix_scan_expr(root, splan->limitCount, rtoffset, 1);
}
break;
case T_Agg:
@@ -775,9 +834,9 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
* variable refs, so fix_scan_expr works for them.
*/
wplan->startOffset =
- fix_scan_expr(root, wplan->startOffset, rtoffset);
+ fix_scan_expr(root, wplan->startOffset, rtoffset, 1);
wplan->endOffset =
- fix_scan_expr(root, wplan->endOffset, rtoffset);
+ fix_scan_expr(root, wplan->endOffset, rtoffset, 1);
}
break;
case T_Result:
@@ -793,13 +852,15 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
else
{
splan->plan.targetlist =
- fix_scan_list(root, splan->plan.targetlist, rtoffset);
+ fix_scan_list(root, splan->plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST(plan));
splan->plan.qual =
- fix_scan_list(root, splan->plan.qual, rtoffset);
+ fix_scan_list(root, splan->plan.qual,
+ rtoffset, NUM_EXEC_QUAL(plan));
}
/* resconstantqual can't contain any subplan variable refs */
splan->resconstantqual =
- fix_scan_expr(root, splan->resconstantqual, rtoffset);
+ fix_scan_expr(root, splan->resconstantqual, rtoffset, 1);
}
break;
case T_ProjectSet:
@@ -813,7 +874,8 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
Assert(splan->plan.qual == NIL);
splan->withCheckOptionLists =
- fix_scan_list(root, splan->withCheckOptionLists, rtoffset);
+ fix_scan_list(root, splan->withCheckOptionLists,
+ rtoffset, 1);
if (splan->returningLists)
{
@@ -874,18 +936,18 @@ set_plan_refs(PlannerInfo *root, Plan *plan, int rtoffset)
fix_join_expr(root, splan->onConflictSet,
NULL, itlist,
linitial_int(splan->resultRelations),
- rtoffset);
+ rtoffset, NUM_EXEC_QUAL(plan));
splan->onConflictWhere = (Node *)
fix_join_expr(root, (List *) splan->onConflictWhere,
NULL, itlist,
linitial_int(splan->resultRelations),
- rtoffset);
+ rtoffset, NUM_EXEC_QUAL(plan));
pfree(itlist);
splan->exclRelTlist =
- fix_scan_list(root, splan->exclRelTlist, rtoffset);
+ fix_scan_list(root, splan->exclRelTlist, rtoffset, 1);
}
splan->nominalRelation += rtoffset;
@@ -1026,19 +1088,24 @@ set_indexonlyscan_references(PlannerInfo *root,
(Node *) plan->scan.plan.targetlist,
index_itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST((Plan *) plan));
plan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) plan->scan.plan.qual,
index_itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) plan));
/* indexqual is already transformed to reference index columns */
- plan->indexqual = fix_scan_list(root, plan->indexqual, rtoffset);
+ plan->indexqual = fix_scan_list(root, plan->indexqual,
+ rtoffset, 1);
/* indexorderby is already transformed to reference index columns */
- plan->indexorderby = fix_scan_list(root, plan->indexorderby, rtoffset);
+ plan->indexorderby = fix_scan_list(root, plan->indexorderby,
+ rtoffset, 1);
/* indextlist must NOT be transformed to reference index columns */
- plan->indextlist = fix_scan_list(root, plan->indextlist, rtoffset);
+ plan->indextlist = fix_scan_list(root, plan->indextlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) plan));
pfree(index_itlist);
@@ -1084,9 +1151,11 @@ set_subqueryscan_references(PlannerInfo *root,
*/
plan->scan.scanrelid += rtoffset;
plan->scan.plan.targetlist =
- fix_scan_list(root, plan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, plan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) plan));
plan->scan.plan.qual =
- fix_scan_list(root, plan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, plan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL((Plan *) plan));
result = (Plan *) plan;
}
@@ -1202,29 +1271,34 @@ set_foreignscan_references(PlannerInfo *root,
(Node *) fscan->scan.plan.targetlist,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST((Plan *) fscan));
fscan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) fscan->scan.plan.qual,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_exprs = (List *)
fix_upper_expr(root,
(Node *) fscan->fdw_exprs,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_recheck_quals = (List *)
fix_upper_expr(root,
(Node *) fscan->fdw_recheck_quals,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) fscan));
pfree(itlist);
/* fdw_scan_tlist itself just needs fix_scan_list() adjustments */
fscan->fdw_scan_tlist =
- fix_scan_list(root, fscan->fdw_scan_tlist, rtoffset);
+ fix_scan_list(root, fscan->fdw_scan_tlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) fscan));
}
else
{
@@ -1233,13 +1307,17 @@ set_foreignscan_references(PlannerInfo *root,
* way
*/
fscan->scan.plan.targetlist =
- fix_scan_list(root, fscan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, fscan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) fscan));
fscan->scan.plan.qual =
- fix_scan_list(root, fscan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, fscan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_exprs =
- fix_scan_list(root, fscan->fdw_exprs, rtoffset);
+ fix_scan_list(root, fscan->fdw_exprs,
+ rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
fscan->fdw_recheck_quals =
- fix_scan_list(root, fscan->fdw_recheck_quals, rtoffset);
+ fix_scan_list(root, fscan->fdw_recheck_quals,
+ rtoffset, NUM_EXEC_QUAL((Plan *) fscan));
}
fscan->fs_relids = offset_relid_set(fscan->fs_relids, rtoffset);
@@ -1270,33 +1348,40 @@ set_customscan_references(PlannerInfo *root,
(Node *) cscan->scan.plan.targetlist,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST((Plan *) cscan));
cscan->scan.plan.qual = (List *)
fix_upper_expr(root,
(Node *) cscan->scan.plan.qual,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) cscan));
cscan->custom_exprs = (List *)
fix_upper_expr(root,
(Node *) cscan->custom_exprs,
itlist,
INDEX_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) cscan));
pfree(itlist);
/* custom_scan_tlist itself just needs fix_scan_list() adjustments */
cscan->custom_scan_tlist =
- fix_scan_list(root, cscan->custom_scan_tlist, rtoffset);
+ fix_scan_list(root, cscan->custom_scan_tlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) cscan));
}
else
{
/* Adjust tlist, qual, custom_exprs in the standard way */
cscan->scan.plan.targetlist =
- fix_scan_list(root, cscan->scan.plan.targetlist, rtoffset);
+ fix_scan_list(root, cscan->scan.plan.targetlist,
+ rtoffset, NUM_EXEC_TLIST((Plan *) cscan));
cscan->scan.plan.qual =
- fix_scan_list(root, cscan->scan.plan.qual, rtoffset);
+ fix_scan_list(root, cscan->scan.plan.qual,
+ rtoffset, NUM_EXEC_QUAL((Plan *) cscan));
cscan->custom_exprs =
- fix_scan_list(root, cscan->custom_exprs, rtoffset);
+ fix_scan_list(root, cscan->custom_exprs,
+ rtoffset, NUM_EXEC_QUAL((Plan *) cscan));
}
/* Adjust child plan-nodes recursively, if needed */
@@ -1458,7 +1543,8 @@ set_hash_references(PlannerInfo *root, Plan *plan, int rtoffset)
(Node *) hplan->hashkeys,
outer_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL(plan));
/* Hash doesn't project */
set_dummy_tlist_references(plan, rtoffset);
@@ -1623,6 +1709,40 @@ fix_param_node(PlannerInfo *root, Param *p)
return (Node *) copyObject(p);
}
+/*
+ * fix_alternative_subplan
+ * Do set_plan_references processing on an AlternativeSubPlan
+ *
+ * Choose one of the alternative implementations and return just that one,
+ * discarding the rest of the AlternativeSubPlan structure.
+ * Note: caller must still recurse into the result!
+ *
+ * We don't make any attempt to fix up cost estimates in the parent
+ * plan node or higher-level nodes.
+ */
+static Node *
+fix_alternative_subplan(AlternativeSubPlan *asplan, double num_exec)
+{
+ SubPlan *subplan1;
+ SubPlan *subplan2;
+ Cost cost1;
+ Cost cost2;
+
+ /* Currently there will always be exactly 2 alternatives */
+ Assert(list_length(asplan->subplans) == 2);
+ subplan1 = (SubPlan *) linitial(asplan->subplans);
+ subplan2 = (SubPlan *) lsecond(asplan->subplans);
+
+ /* Choose the one that's cheaper assuming num_exec executions */
+ cost1 = subplan1->startup_cost + num_exec * subplan1->per_call_cost;
+ cost2 = subplan2->startup_cost + num_exec * subplan2->per_call_cost;
+
+ if (cost1 < cost2)
+ return (Node *) subplan1;
+ else
+ return (Node *) subplan2;
+}
+
/*
* fix_scan_expr
* Do set_plan_references processing on a scan-level expression
@@ -1630,21 +1750,24 @@ fix_param_node(PlannerInfo *root, Param *p)
* This consists of incrementing all Vars' varnos by rtoffset,
* replacing PARAM_MULTIEXPR Params, expanding PlaceHolderVars,
* replacing Aggref nodes that should be replaced by initplan output Params,
+ * choosing the best implementation for AlternativeSubPlans,
* looking up operator opcode info for OpExpr and related nodes,
* and adding OIDs from regclass Const nodes into root->glob->relationOids.
*/
static Node *
-fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset)
+fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset, double num_exec)
{
fix_scan_expr_context context;
context.root = root;
context.rtoffset = rtoffset;
+ context.num_exec = num_exec;
if (rtoffset != 0 ||
root->multiexpr_params != NIL ||
root->glob->lastPHId != 0 ||
- root->minmax_aggs != NIL)
+ root->minmax_aggs != NIL ||
+ root->hasAlternativeSubPlans)
{
return fix_scan_expr_mutator(node, &context);
}
@@ -1655,7 +1778,8 @@ fix_scan_expr(PlannerInfo *root, Node *node, int rtoffset)
* are no MULTIEXPR subqueries then we don't need to replace
* PARAM_MULTIEXPR Params, and if there are no placeholders anywhere
* we won't need to remove them, and if there are no minmax Aggrefs we
- * won't need to replace them. Then it's OK to just scribble on the
+ * won't need to replace them, and if there are no AlternativeSubPlans
+ * we won't need to remove them. Then it's OK to just scribble on the
* input node tree instead of copying (since the only change, filling
* in any unset opfuncid fields, is harmless). This saves just enough
* cycles to be noticeable on trivial queries.
@@ -1729,6 +1853,10 @@ fix_scan_expr_mutator(Node *node, fix_scan_expr_context *context)
return fix_scan_expr_mutator((Node *) phv->phexpr, context);
}
+ if (IsA(node, AlternativeSubPlan))
+ return fix_scan_expr_mutator(fix_alternative_subplan((AlternativeSubPlan *) node,
+ context->num_exec),
+ context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node, fix_scan_expr_mutator,
(void *) context);
@@ -1740,6 +1868,7 @@ fix_scan_expr_walker(Node *node, fix_scan_expr_context *context)
if (node == NULL)
return false;
Assert(!IsA(node, PlaceHolderVar));
+ Assert(!IsA(node, AlternativeSubPlan));
fix_expr_common(context->root, node);
return expression_tree_walker(node, fix_scan_expr_walker,
(void *) context);
@@ -1776,7 +1905,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
outer_itlist,
inner_itlist,
(Index) 0,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) join));
/* Now do join-type-specific stuff */
if (IsA(join, NestLoop))
@@ -1792,7 +1922,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
(Node *) nlp->paramval,
outer_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST(outer_plan));
/* Check we replaced any PlaceHolderVar with simple Var */
if (!(IsA(nlp->paramval, Var) &&
nlp->paramval->varno == OUTER_VAR))
@@ -1808,7 +1939,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
outer_itlist,
inner_itlist,
(Index) 0,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) join));
}
else if (IsA(join, HashJoin))
{
@@ -1819,7 +1951,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
outer_itlist,
inner_itlist,
(Index) 0,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) join));
/*
* HashJoin's hashkeys are used to look for matching tuples from its
@@ -1829,7 +1962,8 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
(Node *) hj->hashkeys,
outer_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) join));
}
/*
@@ -1867,13 +2001,15 @@ set_join_references(PlannerInfo *root, Join *join, int rtoffset)
outer_itlist,
inner_itlist,
(Index) 0,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST((Plan *) join));
join->plan.qual = fix_join_expr(root,
join->plan.qual,
outer_itlist,
inner_itlist,
(Index) 0,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL((Plan *) join));
pfree(outer_itlist);
pfree(inner_itlist);
@@ -1926,14 +2062,16 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset)
(Node *) tle->expr,
subplan_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST(plan));
}
else
newexpr = fix_upper_expr(root,
(Node *) tle->expr,
subplan_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST(plan));
tle = flatCopyTargetEntry(tle);
tle->expr = (Expr *) newexpr;
output_targetlist = lappend(output_targetlist, tle);
@@ -1945,7 +2083,8 @@ set_upper_references(PlannerInfo *root, Plan *plan, int rtoffset)
(Node *) plan->qual,
subplan_itlist,
OUTER_VAR,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_QUAL(plan));
pfree(subplan_itlist);
}
@@ -2389,6 +2528,7 @@ search_indexed_tlist_for_sortgroupref(Expr *node,
* 'acceptable_rel' is either zero or the rangetable index of a relation
* whose Vars may appear in the clause without provoking an error
* 'rtoffset': how much to increment varnos by
+ * 'num_exec': estimated number of executions of expression
*
* Returns the new expression tree. The original clause structure is
* not modified.
@@ -2399,7 +2539,8 @@ fix_join_expr(PlannerInfo *root,
indexed_tlist *outer_itlist,
indexed_tlist *inner_itlist,
Index acceptable_rel,
- int rtoffset)
+ int rtoffset,
+ double num_exec)
{
fix_join_expr_context context;
@@ -2408,6 +2549,7 @@ fix_join_expr(PlannerInfo *root,
context.inner_itlist = inner_itlist;
context.acceptable_rel = acceptable_rel;
context.rtoffset = rtoffset;
+ context.num_exec = num_exec;
return (List *) fix_join_expr_mutator((Node *) clauses, &context);
}
@@ -2502,6 +2644,10 @@ fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
/* Special cases (apply only AFTER failing to match to lower tlist) */
if (IsA(node, Param))
return fix_param_node(context->root, (Param *) node);
+ if (IsA(node, AlternativeSubPlan))
+ return fix_join_expr_mutator(fix_alternative_subplan((AlternativeSubPlan *) node,
+ context->num_exec),
+ context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node,
fix_join_expr_mutator,
@@ -2533,6 +2679,7 @@ fix_join_expr_mutator(Node *node, fix_join_expr_context *context)
* 'subplan_itlist': indexed target list for subplan (or index)
* 'newvarno': varno to use for Vars referencing tlist elements
* 'rtoffset': how much to increment varnos by
+ * 'num_exec': estimated number of executions of expression
*
* The resulting tree is a copy of the original in which all Var nodes have
* varno = newvarno, varattno = resno of corresponding targetlist element.
@@ -2543,7 +2690,8 @@ fix_upper_expr(PlannerInfo *root,
Node *node,
indexed_tlist *subplan_itlist,
Index newvarno,
- int rtoffset)
+ int rtoffset,
+ double num_exec)
{
fix_upper_expr_context context;
@@ -2551,6 +2699,7 @@ fix_upper_expr(PlannerInfo *root,
context.subplan_itlist = subplan_itlist;
context.newvarno = newvarno;
context.rtoffset = rtoffset;
+ context.num_exec = num_exec;
return fix_upper_expr_mutator(node, &context);
}
@@ -2623,6 +2772,10 @@ fix_upper_expr_mutator(Node *node, fix_upper_expr_context *context)
}
/* If no match, just fall through to process it normally */
}
+ if (IsA(node, AlternativeSubPlan))
+ return fix_upper_expr_mutator(fix_alternative_subplan((AlternativeSubPlan *) node,
+ context->num_exec),
+ context);
fix_expr_common(context->root, node);
return expression_tree_mutator(node,
fix_upper_expr_mutator,
@@ -2687,7 +2840,8 @@ set_returning_clause_references(PlannerInfo *root,
itlist,
NULL,
resultRelation,
- rtoffset);
+ rtoffset,
+ NUM_EXEC_TLIST(topplan));
pfree(itlist);
diff --git a/src/backend/optimizer/plan/subselect.c b/src/backend/optimizer/plan/subselect.c
index 6eb794669f..79cc2a386d 100644
--- a/src/backend/optimizer/plan/subselect.c
+++ b/src/backend/optimizer/plan/subselect.c
@@ -247,7 +247,7 @@ make_subplan(PlannerInfo *root, Query *orig_subquery,
* likely to be better (it depends on the expected number of executions of
* the EXISTS qual, and we are much too early in planning the outer query
* to be able to guess that). So we generate both plans, if possible, and
- * leave it to the executor to decide which to use.
+ * leave it to setrefs.c to decide which to use.
*/
if (simple_exists && IsA(result, SubPlan))
{
@@ -298,10 +298,11 @@ make_subplan(PlannerInfo *root, Query *orig_subquery,
Assert(hashplan->parParam == NIL);
Assert(hashplan->useHashTable);
- /* Leave it to the executor to decide which plan to use */
+ /* Leave it to setrefs.c to decide which plan to use */
asplan = makeNode(AlternativeSubPlan);
asplan->subplans = list_make2(result, hashplan);
result = (Node *) asplan;
+ root->hasAlternativeSubPlans = true;
}
}
}
diff --git a/src/include/nodes/pathnodes.h b/src/include/nodes/pathnodes.h
index 485d1b06c9..dbe86e7af6 100644
--- a/src/include/nodes/pathnodes.h
+++ b/src/include/nodes/pathnodes.h
@@ -347,6 +347,7 @@ struct PlannerInfo
bool hasHavingQual; /* true if havingQual was non-null */
bool hasPseudoConstantQuals; /* true if any RestrictInfo has
* pseudoconstant = true */
+ bool hasAlternativeSubPlans; /* true if we've made any of those */
bool hasRecursion; /* true if planning a recursive WITH item */
/* These fields are used only when hasRecursion is true: */
diff --git a/src/include/nodes/primnodes.h b/src/include/nodes/primnodes.h
index d73be2ad46..fd65ee8f9c 100644
--- a/src/include/nodes/primnodes.h
+++ b/src/include/nodes/primnodes.h
@@ -736,6 +736,9 @@ typedef struct SubPlan
/*
* AlternativeSubPlan - expression node for a choice among SubPlans
*
+ * This is used only transiently during planning: by the time the plan
+ * reaches the executor, all AlternativeSubPlan nodes have been removed.
+ *
* The subplans are given as a List so that the node definition need not
* change if there's ever more than two alternatives. For the moment,
* though, there are always exactly two; and the first one is the fast-start
diff --git a/src/test/regress/expected/insert_conflict.out b/src/test/regress/expected/insert_conflict.out
index 1338b2b23e..ff157ceb1c 100644
--- a/src/test/regress/expected/insert_conflict.out
+++ b/src/test/regress/expected/insert_conflict.out
@@ -50,14 +50,12 @@ explain (costs off) insert into insertconflicttest values(0, 'Crowberry') on con
Insert on insertconflicttest
Conflict Resolution: UPDATE
Conflict Arbiter Indexes: op_index_key, collation_index_key, both_index_key
- Conflict Filter: (alternatives: SubPlan 1 or hashed SubPlan 2)
+ Conflict Filter: (SubPlan 1)
-> Result
SubPlan 1
-> Index Only Scan using both_index_expr_key on insertconflicttest ii
Index Cond: (key = excluded.key)
- SubPlan 2
- -> Seq Scan on insertconflicttest ii_1
-(10 rows)
+(8 rows)
-- Neither collation nor operator class specifications are required --
-- supplying them merely *limits* matches to indexes with matching opclasses
diff --git a/src/test/regress/expected/subselect.out b/src/test/regress/expected/subselect.out
index b81923f2e7..9d56cdacf3 100644
--- a/src/test/regress/expected/subselect.out
+++ b/src/test/regress/expected/subselect.out
@@ -874,6 +874,53 @@ select * from int8_tbl where q1 in (select c1 from inner_text);
(2 rows)
rollback; -- to get rid of the bogus operator
+--
+-- Test resolution of hashed vs non-hashed implementation of EXISTS subplan
+--
+explain (costs off)
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0);
+ QUERY PLAN
+--------------------------------------------------------------
+ Aggregate
+ -> Seq Scan on tenk1 t
+ Filter: ((hashed SubPlan 2) OR (ten < 0))
+ SubPlan 2
+ -> Index Only Scan using tenk1_unique1 on tenk1 k
+(5 rows)
+
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0);
+ count
+-------
+ 10000
+(1 row)
+
+explain (costs off)
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0)
+ and thousand = 1;
+ QUERY PLAN
+--------------------------------------------------------------
+ Aggregate
+ -> Bitmap Heap Scan on tenk1 t
+ Recheck Cond: (thousand = 1)
+ Filter: ((SubPlan 1) OR (ten < 0))
+ -> Bitmap Index Scan on tenk1_thous_tenthous
+ Index Cond: (thousand = 1)
+ SubPlan 1
+ -> Index Only Scan using tenk1_unique1 on tenk1 k
+ Index Cond: (unique1 = t.unique2)
+(9 rows)
+
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0)
+ and thousand = 1;
+ count
+-------
+ 10
+(1 row)
+
--
-- Test case for planner bug with nested EXISTS handling
--
diff --git a/src/test/regress/expected/updatable_views.out b/src/test/regress/expected/updatable_views.out
index 5de53f2782..caed1c19ec 100644
--- a/src/test/regress/expected/updatable_views.out
+++ b/src/test/regress/expected/updatable_views.out
@@ -1869,9 +1869,7 @@ EXPLAIN (costs off) INSERT INTO rw_view1 VALUES (5);
SubPlan 1
-> Index Only Scan using ref_tbl_pkey on ref_tbl r
Index Cond: (a = b.a)
- SubPlan 2
- -> Seq Scan on ref_tbl r_1
-(7 rows)
+(5 rows)
EXPLAIN (costs off) UPDATE rw_view1 SET a = a + 5;
QUERY PLAN
@@ -1885,9 +1883,7 @@ EXPLAIN (costs off) UPDATE rw_view1 SET a = a + 5;
SubPlan 1
-> Index Only Scan using ref_tbl_pkey on ref_tbl r_1
Index Cond: (a = b.a)
- SubPlan 2
- -> Seq Scan on ref_tbl r_2
-(11 rows)
+(9 rows)
DROP TABLE base_tbl, ref_tbl CASCADE;
NOTICE: drop cascades to view rw_view1
@@ -2301,8 +2297,8 @@ SELECT * FROM v1 WHERE a=8;
EXPLAIN (VERBOSE, COSTS OFF)
UPDATE v1 SET a=100 WHERE snoop(a) AND leakproof(a) AND a < 7 AND a != 6;
- QUERY PLAN
----------------------------------------------------------------------------------------------------------------------------
+ QUERY PLAN
+-----------------------------------------------------------------------------------------
Update on public.t1
Update on public.t1
Update on public.t11 t1_1
@@ -2311,32 +2307,26 @@ UPDATE v1 SET a=100 WHERE snoop(a) AND leakproof(a) AND a < 7 AND a != 6;
-> Index Scan using t1_a_idx on public.t1
Output: 100, t1.b, t1.c, t1.ctid
Index Cond: ((t1.a > 5) AND (t1.a < 7))
- Filter: ((t1.a <> 6) AND (alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1.a) AND leakproof(t1.a))
+ Filter: ((t1.a <> 6) AND (SubPlan 1) AND snoop(t1.a) AND leakproof(t1.a))
SubPlan 1
-> Append
-> Seq Scan on public.t12 t12_1
Filter: (t12_1.a = t1.a)
-> Seq Scan on public.t111 t12_2
Filter: (t12_2.a = t1.a)
- SubPlan 2
- -> Append
- -> Seq Scan on public.t12 t12_4
- Output: t12_4.a
- -> Seq Scan on public.t111 t12_5
- Output: t12_5.a
-> Index Scan using t11_a_idx on public.t11 t1_1
Output: 100, t1_1.b, t1_1.c, t1_1.d, t1_1.ctid
Index Cond: ((t1_1.a > 5) AND (t1_1.a < 7))
- Filter: ((t1_1.a <> 6) AND (alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_1.a) AND leakproof(t1_1.a))
+ Filter: ((t1_1.a <> 6) AND (SubPlan 1) AND snoop(t1_1.a) AND leakproof(t1_1.a))
-> Index Scan using t12_a_idx on public.t12 t1_2
Output: 100, t1_2.b, t1_2.c, t1_2.e, t1_2.ctid
Index Cond: ((t1_2.a > 5) AND (t1_2.a < 7))
- Filter: ((t1_2.a <> 6) AND (alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_2.a) AND leakproof(t1_2.a))
+ Filter: ((t1_2.a <> 6) AND (SubPlan 1) AND snoop(t1_2.a) AND leakproof(t1_2.a))
-> Index Scan using t111_a_idx on public.t111 t1_3
Output: 100, t1_3.b, t1_3.c, t1_3.d, t1_3.e, t1_3.ctid
Index Cond: ((t1_3.a > 5) AND (t1_3.a < 7))
- Filter: ((t1_3.a <> 6) AND (alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_3.a) AND leakproof(t1_3.a))
-(33 rows)
+ Filter: ((t1_3.a <> 6) AND (SubPlan 1) AND snoop(t1_3.a) AND leakproof(t1_3.a))
+(27 rows)
UPDATE v1 SET a=100 WHERE snoop(a) AND leakproof(a) AND a < 7 AND a != 6;
SELECT * FROM v1 WHERE a=100; -- Nothing should have been changed to 100
@@ -2351,8 +2341,8 @@ SELECT * FROM t1 WHERE a=100; -- Nothing should have been changed to 100
EXPLAIN (VERBOSE, COSTS OFF)
UPDATE v1 SET a=a+1 WHERE snoop(a) AND leakproof(a) AND a = 8;
- QUERY PLAN
----------------------------------------------------------------------------------------------------------
+ QUERY PLAN
+-------------------------------------------------------------------------
Update on public.t1
Update on public.t1
Update on public.t11 t1_1
@@ -2361,32 +2351,26 @@ UPDATE v1 SET a=a+1 WHERE snoop(a) AND leakproof(a) AND a = 8;
-> Index Scan using t1_a_idx on public.t1
Output: (t1.a + 1), t1.b, t1.c, t1.ctid
Index Cond: ((t1.a > 5) AND (t1.a = 8))
- Filter: ((alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1.a) AND leakproof(t1.a))
+ Filter: ((SubPlan 1) AND snoop(t1.a) AND leakproof(t1.a))
SubPlan 1
-> Append
-> Seq Scan on public.t12 t12_1
Filter: (t12_1.a = t1.a)
-> Seq Scan on public.t111 t12_2
Filter: (t12_2.a = t1.a)
- SubPlan 2
- -> Append
- -> Seq Scan on public.t12 t12_4
- Output: t12_4.a
- -> Seq Scan on public.t111 t12_5
- Output: t12_5.a
-> Index Scan using t11_a_idx on public.t11 t1_1
Output: (t1_1.a + 1), t1_1.b, t1_1.c, t1_1.d, t1_1.ctid
Index Cond: ((t1_1.a > 5) AND (t1_1.a = 8))
- Filter: ((alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_1.a) AND leakproof(t1_1.a))
+ Filter: ((SubPlan 1) AND snoop(t1_1.a) AND leakproof(t1_1.a))
-> Index Scan using t12_a_idx on public.t12 t1_2
Output: (t1_2.a + 1), t1_2.b, t1_2.c, t1_2.e, t1_2.ctid
Index Cond: ((t1_2.a > 5) AND (t1_2.a = 8))
- Filter: ((alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_2.a) AND leakproof(t1_2.a))
+ Filter: ((SubPlan 1) AND snoop(t1_2.a) AND leakproof(t1_2.a))
-> Index Scan using t111_a_idx on public.t111 t1_3
Output: (t1_3.a + 1), t1_3.b, t1_3.c, t1_3.d, t1_3.e, t1_3.ctid
Index Cond: ((t1_3.a > 5) AND (t1_3.a = 8))
- Filter: ((alternatives: SubPlan 1 or hashed SubPlan 2) AND snoop(t1_3.a) AND leakproof(t1_3.a))
-(33 rows)
+ Filter: ((SubPlan 1) AND snoop(t1_3.a) AND leakproof(t1_3.a))
+(27 rows)
UPDATE v1 SET a=a+1 WHERE snoop(a) AND leakproof(a) AND a = 8;
NOTICE: snooped value: 8
diff --git a/src/test/regress/sql/subselect.sql b/src/test/regress/sql/subselect.sql
index cce8ebdb3d..a25cb6fc5c 100644
--- a/src/test/regress/sql/subselect.sql
+++ b/src/test/regress/sql/subselect.sql
@@ -509,6 +509,23 @@ select * from int8_tbl where q1 in (select c1 from inner_text);
rollback; -- to get rid of the bogus operator
+--
+-- Test resolution of hashed vs non-hashed implementation of EXISTS subplan
+--
+explain (costs off)
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0);
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0);
+
+explain (costs off)
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0)
+ and thousand = 1;
+select count(*) from tenk1 t
+where (exists(select 1 from tenk1 k where k.unique1 = t.unique2) or ten < 0)
+ and thousand = 1;
+
--
-- Test case for planner bug with nested EXISTS handling
--
diff --git a/src/backend/executor/execExpr.c b/src/backend/executor/execExpr.c
index 236413f62a..868f8b0858 100644
--- a/src/backend/executor/execExpr.c
+++ b/src/backend/executor/execExpr.c
@@ -1104,23 +1104,6 @@ ExecInitExprRec(Expr *node, ExprState *state,
break;
}
- case T_AlternativeSubPlan:
- {
- AlternativeSubPlan *asplan = (AlternativeSubPlan *) node;
- AlternativeSubPlanState *asstate;
-
- if (!state->parent)
- elog(ERROR, "AlternativeSubPlan found with no parent plan");
-
- asstate = ExecInitAlternativeSubPlan(asplan, state->parent);
-
- scratch.opcode = EEOP_ALTERNATIVE_SUBPLAN;
- scratch.d.alternative_subplan.asstate = asstate;
-
- ExprEvalPushStep(state, &scratch);
- break;
- }
-
case T_FieldSelect:
{
FieldSelect *fselect = (FieldSelect *) node;
diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index b812bbacee..26c2b49632 100644
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -431,7 +431,6 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
&&CASE_EEOP_GROUPING_FUNC,
&&CASE_EEOP_WINDOW_FUNC,
&&CASE_EEOP_SUBPLAN,
- &&CASE_EEOP_ALTERNATIVE_SUBPLAN,
&&CASE_EEOP_AGG_STRICT_DESERIALIZE,
&&CASE_EEOP_AGG_DESERIALIZE,
&&CASE_EEOP_AGG_STRICT_INPUT_CHECK_ARGS,
@@ -1536,14 +1535,6 @@ ExecInterpExpr(ExprState *state, ExprContext *econtext, bool *isnull)
EEO_NEXT();
}
- EEO_CASE(EEOP_ALTERNATIVE_SUBPLAN)
- {
- /* too complex for an inline implementation */
- ExecEvalAlternativeSubPlan(state, op, econtext);
-
- EEO_NEXT();
- }
-
/* evaluate a strict aggregate deserialization function */
EEO_CASE(EEOP_AGG_STRICT_DESERIALIZE)
{
@@ -3868,20 +3859,6 @@ ExecEvalSubPlan(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
*op->resvalue = ExecSubPlan(sstate, econtext, op->resnull);
}
-/*
- * Hand off evaluation of an alternative subplan to nodeSubplan.c
- */
-void
-ExecEvalAlternativeSubPlan(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
-{
- AlternativeSubPlanState *asstate = op->d.alternative_subplan.asstate;
-
- /* could potentially be nested, so make sure there's enough stack */
- check_stack_depth();
-
- *op->resvalue = ExecAlternativeSubPlan(asstate, econtext, op->resnull);
-}
-
/*
* Evaluate a wholerow Var expression.
*
diff --git a/src/backend/executor/nodeSubplan.c b/src/backend/executor/nodeSubplan.c
index 9a7962518e..9a706df5f0 100644
--- a/src/backend/executor/nodeSubplan.c
+++ b/src/backend/executor/nodeSubplan.c
@@ -1303,83 +1303,3 @@ ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent)
parent->chgParam = bms_add_member(parent->chgParam, paramid);
}
}
-
-
-/*
- * ExecInitAlternativeSubPlan
- *
- * Initialize for execution of one of a set of alternative subplans.
- */
-AlternativeSubPlanState *
-ExecInitAlternativeSubPlan(AlternativeSubPlan *asplan, PlanState *parent)
-{
- AlternativeSubPlanState *asstate = makeNode(AlternativeSubPlanState);
- double num_calls;
- SubPlan *subplan1;
- SubPlan *subplan2;
- Cost cost1;
- Cost cost2;
- ListCell *lc;
-
- asstate->subplan = asplan;
-
- /*
- * Initialize subplans. (Can we get away with only initializing the one
- * we're going to use?)
- */
- foreach(lc, asplan->subplans)
- {
- SubPlan *sp = lfirst_node(SubPlan, lc);
- SubPlanState *sps = ExecInitSubPlan(sp, parent);
-
- asstate->subplans = lappend(asstate->subplans, sps);
- parent->subPlan = lappend(parent->subPlan, sps);
- }
-
- /*
- * Select the one to be used. For this, we need an estimate of the number
- * of executions of the subplan. We use the number of output rows
- * expected from the parent plan node. This is a good estimate if we are
- * in the parent's targetlist, and an underestimate (but probably not by
- * more than a factor of 2) if we are in the qual.
- */
- num_calls = parent->plan->plan_rows;
-
- /*
- * The planner saved enough info so that we don't have to work very hard
- * to estimate the total cost, given the number-of-calls estimate.
- */
- Assert(list_length(asplan->subplans) == 2);
- subplan1 = (SubPlan *) linitial(asplan->subplans);
- subplan2 = (SubPlan *) lsecond(asplan->subplans);
-
- cost1 = subplan1->startup_cost + num_calls * subplan1->per_call_cost;
- cost2 = subplan2->startup_cost + num_calls * subplan2->per_call_cost;
-
- if (cost1 < cost2)
- asstate->active = 0;
- else
- asstate->active = 1;
-
- return asstate;
-}
-
-/*
- * ExecAlternativeSubPlan
- *
- * Execute one of a set of alternative subplans.
- *
- * Note: in future we might consider changing to different subplans on the
- * fly, in case the original rowcount estimate turns out to be way off.
- */
-Datum
-ExecAlternativeSubPlan(AlternativeSubPlanState *node,
- ExprContext *econtext,
- bool *isNull)
-{
- /* Just pass control to the active subplan */
- SubPlanState *activesp = list_nth_node(SubPlanState,
- node->subplans, node->active);
-
- return ExecSubPlan(activesp, econtext, isNull);
-}
diff --git a/src/backend/jit/llvm/llvmjit_expr.c b/src/backend/jit/llvm/llvmjit_expr.c
index cca5c117a0..eb1dea658c 100644
--- a/src/backend/jit/llvm/llvmjit_expr.c
+++ b/src/backend/jit/llvm/llvmjit_expr.c
@@ -1918,12 +1918,6 @@ llvm_compile_expr(ExprState *state)
LLVMBuildBr(b, opblocks[opno + 1]);
break;
- case EEOP_ALTERNATIVE_SUBPLAN:
- build_EvalXFunc(b, mod, "ExecEvalAlternativeSubPlan",
- v_state, op, v_econtext);
- LLVMBuildBr(b, opblocks[opno + 1]);
- break;
-
case EEOP_AGG_STRICT_DESERIALIZE:
case EEOP_AGG_DESERIALIZE:
{
diff --git a/src/backend/jit/llvm/llvmjit_types.c b/src/backend/jit/llvm/llvmjit_types.c
index 0a93d5f665..1ed3cafa2f 100644
--- a/src/backend/jit/llvm/llvmjit_types.c
+++ b/src/backend/jit/llvm/llvmjit_types.c
@@ -102,7 +102,6 @@ void *referenced_functions[] =
ExecAggTransReparent,
ExecEvalAggOrderedTransDatum,
ExecEvalAggOrderedTransTuple,
- ExecEvalAlternativeSubPlan,
ExecEvalArrayCoerce,
ExecEvalArrayExpr,
ExecEvalConstraintCheck,
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 60dd80c23c..0e3084325e 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -8192,7 +8192,12 @@ get_rule_expr(Node *node, deparse_context *context,
AlternativeSubPlan *asplan = (AlternativeSubPlan *) node;
ListCell *lc;
- /* As above, this can only happen during EXPLAIN */
+ /*
+ * This case cannot be reached in normal usage, since no
+ * AlternativeSubPlan can appear either in parsetrees or
+ * finished plan trees. We keep it just in case somebody
+ * wants to use this code to print planner data structures.
+ */
appendStringInfoString(buf, "(alternatives: ");
foreach(lc, asplan->subplans)
{
diff --git a/src/include/executor/execExpr.h b/src/include/executor/execExpr.h
index dbe8649a57..b792de1bc9 100644
--- a/src/include/executor/execExpr.h
+++ b/src/include/executor/execExpr.h
@@ -218,7 +218,6 @@ typedef enum ExprEvalOp
EEOP_GROUPING_FUNC,
EEOP_WINDOW_FUNC,
EEOP_SUBPLAN,
- EEOP_ALTERNATIVE_SUBPLAN,
/* aggregation related nodes */
EEOP_AGG_STRICT_DESERIALIZE,
@@ -589,13 +588,6 @@ typedef struct ExprEvalStep
SubPlanState *sstate;
} subplan;
- /* for EEOP_ALTERNATIVE_SUBPLAN */
- struct
- {
- /* out-of-line state, created by nodeSubplan.c */
- AlternativeSubPlanState *asstate;
- } alternative_subplan;
-
/* for EEOP_AGG_*DESERIALIZE */
struct
{
@@ -734,8 +726,6 @@ extern void ExecEvalXmlExpr(ExprState *state, ExprEvalStep *op);
extern void ExecEvalGroupingFunc(ExprState *state, ExprEvalStep *op);
extern void ExecEvalSubPlan(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
-extern void ExecEvalAlternativeSubPlan(ExprState *state, ExprEvalStep *op,
- ExprContext *econtext);
extern void ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op,
ExprContext *econtext);
extern void ExecEvalSysVar(ExprState *state, ExprEvalStep *op,
diff --git a/src/include/executor/nodeSubplan.h b/src/include/executor/nodeSubplan.h
index 83e90b3d07..b629af1f5f 100644
--- a/src/include/executor/nodeSubplan.h
+++ b/src/include/executor/nodeSubplan.h
@@ -18,12 +18,8 @@
extern SubPlanState *ExecInitSubPlan(SubPlan *subplan, PlanState *parent);
-extern AlternativeSubPlanState *ExecInitAlternativeSubPlan(AlternativeSubPlan *asplan, PlanState *parent);
-
extern Datum ExecSubPlan(SubPlanState *node, ExprContext *econtext, bool *isNull);
-extern Datum ExecAlternativeSubPlan(AlternativeSubPlanState *node, ExprContext *econtext, bool *isNull);
-
extern void ExecReScanSetParamPlan(SubPlanState *node, PlanState *parent);
extern void ExecSetParamPlan(SubPlanState *node, ExprContext *econtext);
diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index 0b42dd6f94..7e02afa6ba 100644
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -880,18 +880,6 @@ typedef struct SubPlanState
ExprState *cur_eq_comp; /* equality comparator for LHS vs. table */
} SubPlanState;
-/* ----------------
- * AlternativeSubPlanState node
- * ----------------
- */
-typedef struct AlternativeSubPlanState
-{
- NodeTag type;
- AlternativeSubPlan *subplan; /* expression plan node */
- List *subplans; /* SubPlanStates of alternative subplans */
- int active; /* list index of the one we're using */
-} AlternativeSubPlanState;
-
/*
* DomainConstraintState - one item to check during CoerceToDomain
*
diff --git a/src/include/nodes/nodes.h b/src/include/nodes/nodes.h
index 381d84b4e4..7ddd8c011b 100644
--- a/src/include/nodes/nodes.h
+++ b/src/include/nodes/nodes.h
@@ -213,7 +213,6 @@ typedef enum NodeTag
T_WindowFuncExprState,
T_SetExprState,
T_SubPlanState,
- T_AlternativeSubPlanState,
T_DomainConstraintState,
/*
