Fix an oversight in cbc127917 to handle MERGE correctly

ExecInitModifyTable() forgot to trim MERGE-related lists to exclude
entries for result relations pruned during initial pruning, so fix
that.

While at it, make the function's use of the pruned resultRelations
list, rather than ModifyTable.resultRelations, more consistent.

Reported-by: Alexander Lakhin <exclusion@gmail.com> (via sqlsmith)
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://postgr.es/m/e72c94d9-e5f9-4753-9bc1-69d72bd54b8a@gmail.com

diff --git a/src/backend/executor/nodeModifyTable.c b/src/backend/executor/nodeModifyTable.c
index a15e7863b0d2afd7fa1c9a4738e8a6bc6750cfd4..b0fe50075adf5597bfe4ff8dc5da094389518ace 100644 (file)
--- a/src/backend/executor/nodeModifyTable.c
+++ b/src/backend/executor/nodeModifyTable.c
@@ -3643,14 +3643,15 @@ ExecMergeNotMatched(ModifyTableContext *context, ResultRelInfo *resultRelInfo,
 void
 ExecInitMerge(ModifyTableState *mtstate, EState *estate)
 {
-   ModifyTable *node = (ModifyTable *) mtstate->ps.plan;
+   List       *mergeActionLists = mtstate->mt_mergeActionLists;
+   List       *mergeJoinConditions = mtstate->mt_mergeJoinConditions;
    ResultRelInfo *rootRelInfo = mtstate->rootResultRelInfo;
    ResultRelInfo *resultRelInfo;
    ExprContext *econtext;
    ListCell   *lc;
    int         i;
 
-   if (node->mergeActionLists == NIL)
+   if (mergeActionLists == NIL)
        return;
 
    mtstate->mt_merge_subcommands = 0;
@@ -3667,14 +3668,14 @@ ExecInitMerge(ModifyTableState *mtstate, EState *estate)
     * anything here, do so there too.
     */
    i = 0;
-   foreach(lc, node->mergeActionLists)
+   foreach(lc, mergeActionLists)
    {
        List       *mergeActionList = lfirst(lc);
        Node       *joinCondition;
        TupleDesc   relationDesc;
        ListCell   *l;
 
-       joinCondition = (Node *) list_nth(node->mergeJoinConditions, i);
+       joinCondition = (Node *) list_nth(mergeJoinConditions, i);
        resultRelInfo = mtstate->resultRelInfo + i;
        i++;
        relationDesc = RelationGetDescr(resultRelInfo->ri_RelationDesc);
@@ -4475,6 +4476,8 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
    List       *withCheckOptionLists = NIL;
    List       *returningLists = NIL;
    List       *updateColnosLists = NIL;
+   List       *mergeActionLists = NIL;
+   List       *mergeJoinConditions = NIL;
    ResultRelInfo *resultRelInfo;
    List       *arowmarks;
    ListCell   *l;
@@ -4518,6 +4521,18 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
 
                updateColnosLists = lappend(updateColnosLists, updateColnosList);
            }
+           if (node->mergeActionLists)
+           {
+               List       *mergeActionList = list_nth(node->mergeActionLists, i);
+
+               mergeActionLists = lappend(mergeActionLists, mergeActionList);
+           }
+           if (node->mergeJoinConditions)
+           {
+               List       *mergeJoinCondition = list_nth(node->mergeJoinConditions, i);
+
+               mergeJoinConditions = lappend(mergeJoinConditions, mergeJoinCondition);
+           }
        }
        i++;
    }
@@ -4544,6 +4559,8 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
    mtstate->mt_merge_updated = 0;
    mtstate->mt_merge_deleted = 0;
    mtstate->mt_updateColnosLists = updateColnosLists;
+   mtstate->mt_mergeActionLists = mergeActionLists;
+   mtstate->mt_mergeJoinConditions = mergeJoinConditions;
 
    /*----------
     * Resolve the target relation. This is the same as:
@@ -4556,7 +4573,8 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
     * If it's a partitioned or inherited table, the root partition or
     * appendrel RTE doesn't appear elsewhere in the plan and its RT index is
     * given explicitly in node->rootRelation.  Otherwise, the target relation
-    * is the sole relation in the node->resultRelations list.
+    * is the sole relation in the node->resultRelations list and, since it can
+    * never be pruned, also in the resultRelations list constructed above.
     *----------
     */
    if (node->rootRelation > 0)
@@ -4569,9 +4587,10 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
    else
    {
        Assert(list_length(node->resultRelations) == 1);
+       Assert(list_length(resultRelations) == 1);
        mtstate->rootResultRelInfo = mtstate->resultRelInfo;
        ExecInitResultRelation(estate, mtstate->resultRelInfo,
-                              linitial_int(node->resultRelations));
+                              linitial_int(resultRelations));
    }
 
    /* set up epqstate with dummy subplan data for the moment */
@@ -4599,8 +4618,8 @@ ExecInitModifyTable(ModifyTable *node, EState *estate, int eflags)
        Index       resultRelation = lfirst_int(l);
        List       *mergeActions = NIL;
 
-       if (node->mergeActionLists)
-           mergeActions = list_nth(node->mergeActionLists, i);
+       if (mergeActionLists)
+           mergeActions = list_nth(mergeActionLists, i);
 
        if (resultRelInfo != mtstate->rootResultRelInfo)
        {

diff --git a/src/include/nodes/execnodes.h b/src/include/nodes/execnodes.h
index e2d1dc1e06728167f0445ff048bb5f44e11a6f4b..2625d7e82227db8e82e08674b190d9aa76d3d839 100644 (file)
--- a/src/include/nodes/execnodes.h
+++ b/src/include/nodes/execnodes.h
@@ -1448,10 +1448,13 @@ typedef struct ModifyTableState
    double      mt_merge_deleted;
 
    /*
-    * List of valid updateColnosLists.  Contains only those belonging to
-    * unpruned relations from ModifyTable.updateColnosLists.
+    * Lists of valid updateColnosLists, mergeActionLists, and
+    * mergeJoinConditions.  These contain only entries for unpruned
+    * relations, filtered from the corresponding lists in ModifyTable.
     */
    List       *mt_updateColnosLists;
+   List       *mt_mergeActionLists;
+   List       *mt_mergeJoinConditions;
 } ModifyTableState;
 
 /* ----------------

diff --git a/src/test/regress/expected/partition_prune.out b/src/test/regress/expected/partition_prune.out
index e667503c9610e658bb3b9d5e0264ddb12755650d..6f80b62a3b8b749172cbd7356ac85964c06a57ba 100644 (file)
--- a/src/test/regress/expected/partition_prune.out
+++ b/src/test/regress/expected/partition_prune.out
@@ -4512,6 +4512,83 @@ explain (costs off) execute update_part_abc_view (2, 'a');
 execute update_part_abc_view (2, 'a');
 ERROR:  new row violates check option for view "part_abc_view"
 DETAIL:  Failing row contains (2, a, t).
+-- All pruned.
+explain (costs off) execute update_part_abc_view (3, 'a');
+         QUERY PLAN          
+-----------------------------
+ Update on part_abc
+   ->  Append
+         Subplans Removed: 2
+(3 rows)
+
+execute update_part_abc_view (3, 'a');
+ a | b | c 
+---+---+---
+(0 rows)
+
 deallocate update_part_abc_view;
+-- Runtime pruning on MERGE using a stable function
+create function stable_one() returns int as $$ begin return 1; end; $$ language plpgsql stable;
+explain (costs off)
+merge into part_abc_view pt
+using (select stable_one() as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+                              QUERY PLAN                               
+-----------------------------------------------------------------------
+ Merge on part_abc
+   Merge on part_abc_1
+   ->  Nested Loop
+         ->  Append
+               Subplans Removed: 1
+               ->  Seq Scan on part_abc_1
+                     Filter: ((b <> 'a'::text) AND (a = stable_one()))
+         ->  Materialize
+               ->  Seq Scan on part_abc_1 pt1
+                     Filter: (a = stable_one())
+(10 rows)
+
+merge into part_abc_view pt
+using (select stable_one() as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+ a 
+---
+ 1
+(1 row)
+
+table part_abc_view;
+ a | b | c 
+---+---+---
+ 2 | c | t
+(1 row)
+
+-- All pruned.
+explain (costs off)
+merge into part_abc_view pt
+using (select stable_one() + 2 as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+                      QUERY PLAN                      
+------------------------------------------------------
+ Merge on part_abc
+   ->  Nested Loop
+         ->  Append
+               Subplans Removed: 2
+         ->  Materialize
+               ->  Seq Scan on part_abc_1 pt1
+                     Filter: (a = (stable_one() + 2))
+(7 rows)
+
+merge into part_abc_view pt
+using (select stable_one() + 2 as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+ a 
+---
+(0 rows)
+
+table part_abc_view;
+ a | b | c 
+---+---+---
+ 2 | c | t
+(1 row)
+
 drop view part_abc_view;
 drop table part_abc;

diff --git a/src/test/regress/sql/partition_prune.sql b/src/test/regress/sql/partition_prune.sql
index 730545e86a77408f755b2a3f42cf5fafe70af8e0..86621dcec0b7dffd61ac54db24eb3b751e1e8e20 100644 (file)
--- a/src/test/regress/sql/partition_prune.sql
+++ b/src/test/regress/sql/partition_prune.sql
@@ -1371,6 +1371,31 @@ explain (costs off) execute update_part_abc_view (1, 'd');
 execute update_part_abc_view (1, 'd');
 explain (costs off) execute update_part_abc_view (2, 'a');
 execute update_part_abc_view (2, 'a');
+-- All pruned.
+explain (costs off) execute update_part_abc_view (3, 'a');
+execute update_part_abc_view (3, 'a');
 deallocate update_part_abc_view;
+
+-- Runtime pruning on MERGE using a stable function
+create function stable_one() returns int as $$ begin return 1; end; $$ language plpgsql stable;
+explain (costs off)
+merge into part_abc_view pt
+using (select stable_one() as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+merge into part_abc_view pt
+using (select stable_one() as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+table part_abc_view;
+
+-- All pruned.
+explain (costs off)
+merge into part_abc_view pt
+using (select stable_one() + 2 as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+merge into part_abc_view pt
+using (select stable_one() + 2 as pid) as q join part_abc_1 pt1 on (q.pid = pt1.a) on pt.a = pt1.a
+when matched then delete returning pt.a;
+table part_abc_view;
+
 drop view part_abc_view;
 drop table part_abc;