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-rw-r--r--src/backend/executor/nodeIndexonlyscan.c45
-rw-r--r--src/backend/executor/nodeIndexscan.c45
-rw-r--r--src/backend/executor/nodeMergejoin.c4
-rw-r--r--src/test/isolation/expected/eval-plan-qual.out33
-rw-r--r--src/test/isolation/specs/eval-plan-qual.spec18
5 files changed, 144 insertions, 1 deletions
diff --git a/src/backend/executor/nodeIndexonlyscan.c b/src/backend/executor/nodeIndexonlyscan.c
index 9b7f470ee28..f61b3abf326 100644
--- a/src/backend/executor/nodeIndexonlyscan.c
+++ b/src/backend/executor/nodeIndexonlyscan.c
@@ -421,11 +421,39 @@ ExecEndIndexOnlyScan(IndexOnlyScanState *node)
/* ----------------------------------------------------------------
* ExecIndexOnlyMarkPos
+ *
+ * Note: we assume that no caller attempts to set a mark before having read
+ * at least one tuple. Otherwise, ioss_ScanDesc might still be NULL.
* ----------------------------------------------------------------
*/
void
ExecIndexOnlyMarkPos(IndexOnlyScanState *node)
{
+ EState *estate = node->ss.ps.state;
+
+ if (estate->es_epqTuple != NULL)
+ {
+ /*
+ * We are inside an EvalPlanQual recheck. If a test tuple exists for
+ * this relation, then we shouldn't access the index at all. We would
+ * instead need to save, and later restore, the state of the
+ * es_epqScanDone flag, so that re-fetching the test tuple is
+ * possible. However, given the assumption that no caller sets a mark
+ * at the start of the scan, we can only get here with es_epqScanDone
+ * already set, and so no state need be saved.
+ */
+ Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
+
+ Assert(scanrelid > 0);
+ if (estate->es_epqTupleSet[scanrelid - 1])
+ {
+ /* Verify the claim above */
+ if (!estate->es_epqScanDone[scanrelid - 1])
+ elog(ERROR, "unexpected ExecIndexOnlyMarkPos call in EPQ recheck");
+ return;
+ }
+ }
+
index_markpos(node->ioss_ScanDesc);
}
@@ -436,6 +464,23 @@ ExecIndexOnlyMarkPos(IndexOnlyScanState *node)
void
ExecIndexOnlyRestrPos(IndexOnlyScanState *node)
{
+ EState *estate = node->ss.ps.state;
+
+ if (estate->es_epqTuple != NULL)
+ {
+ /* See comments in ExecIndexOnlyMarkPos */
+ Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
+
+ Assert(scanrelid > 0);
+ if (estate->es_epqTupleSet[scanrelid - 1])
+ {
+ /* Verify the claim above */
+ if (!estate->es_epqScanDone[scanrelid - 1])
+ elog(ERROR, "unexpected ExecIndexOnlyRestrPos call in EPQ recheck");
+ return;
+ }
+ }
+
index_restrpos(node->ioss_ScanDesc);
}
diff --git a/src/backend/executor/nodeIndexscan.c b/src/backend/executor/nodeIndexscan.c
index 54fafa5033f..eed69a0c665 100644
--- a/src/backend/executor/nodeIndexscan.c
+++ b/src/backend/executor/nodeIndexscan.c
@@ -849,11 +849,39 @@ ExecEndIndexScan(IndexScanState *node)
/* ----------------------------------------------------------------
* ExecIndexMarkPos
+ *
+ * Note: we assume that no caller attempts to set a mark before having read
+ * at least one tuple. Otherwise, iss_ScanDesc might still be NULL.
* ----------------------------------------------------------------
*/
void
ExecIndexMarkPos(IndexScanState *node)
{
+ EState *estate = node->ss.ps.state;
+
+ if (estate->es_epqTuple != NULL)
+ {
+ /*
+ * We are inside an EvalPlanQual recheck. If a test tuple exists for
+ * this relation, then we shouldn't access the index at all. We would
+ * instead need to save, and later restore, the state of the
+ * es_epqScanDone flag, so that re-fetching the test tuple is
+ * possible. However, given the assumption that no caller sets a mark
+ * at the start of the scan, we can only get here with es_epqScanDone
+ * already set, and so no state need be saved.
+ */
+ Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
+
+ Assert(scanrelid > 0);
+ if (estate->es_epqTupleSet[scanrelid - 1])
+ {
+ /* Verify the claim above */
+ if (!estate->es_epqScanDone[scanrelid - 1])
+ elog(ERROR, "unexpected ExecIndexMarkPos call in EPQ recheck");
+ return;
+ }
+ }
+
index_markpos(node->iss_ScanDesc);
}
@@ -864,6 +892,23 @@ ExecIndexMarkPos(IndexScanState *node)
void
ExecIndexRestrPos(IndexScanState *node)
{
+ EState *estate = node->ss.ps.state;
+
+ if (estate->es_epqTuple != NULL)
+ {
+ /* See comments in ExecIndexMarkPos */
+ Index scanrelid = ((Scan *) node->ss.ps.plan)->scanrelid;
+
+ Assert(scanrelid > 0);
+ if (estate->es_epqTupleSet[scanrelid - 1])
+ {
+ /* Verify the claim above */
+ if (!estate->es_epqScanDone[scanrelid - 1])
+ elog(ERROR, "unexpected ExecIndexRestrPos call in EPQ recheck");
+ return;
+ }
+ }
+
index_restrpos(node->iss_ScanDesc);
}
diff --git a/src/backend/executor/nodeMergejoin.c b/src/backend/executor/nodeMergejoin.c
index b52946f180a..ec5f82f6a92 100644
--- a/src/backend/executor/nodeMergejoin.c
+++ b/src/backend/executor/nodeMergejoin.c
@@ -1502,6 +1502,10 @@ ExecInitMergeJoin(MergeJoin *node, EState *estate, int eflags)
*
* Currently, only Material wants the extra MARKs, and it will be helpful
* only if eflags doesn't specify REWIND.
+ *
+ * Note that for IndexScan and IndexOnlyScan, it is *necessary* that we
+ * not set mj_ExtraMarks; otherwise we might attempt to set a mark before
+ * the first inner tuple, which they do not support.
*/
if (IsA(innerPlan(node), Material) &&
(eflags & EXEC_FLAG_REWIND) == 0 &&
diff --git a/src/test/isolation/expected/eval-plan-qual.out b/src/test/isolation/expected/eval-plan-qual.out
index 10c784a05f1..eb40717679c 100644
--- a/src/test/isolation/expected/eval-plan-qual.out
+++ b/src/test/isolation/expected/eval-plan-qual.out
@@ -184,3 +184,36 @@ step readwcte: <... completed>
id value
1 tableAValue2
+
+starting permutation: wrjt selectjoinforupdate c2 c1
+step wrjt: UPDATE jointest SET data = 42 WHERE id = 7;
+step selectjoinforupdate:
+ set enable_nestloop to 0;
+ set enable_hashjoin to 0;
+ set enable_seqscan to 0;
+ explain (costs off)
+ select * from jointest a join jointest b on a.id=b.id for update;
+ select * from jointest a join jointest b on a.id=b.id for update;
+ <waiting ...>
+step c2: COMMIT;
+step selectjoinforupdate: <... completed>
+QUERY PLAN
+
+LockRows
+ -> Merge Join
+ Merge Cond: (a.id = b.id)
+ -> Index Scan using jointest_id_idx on jointest a
+ -> Index Scan using jointest_id_idx on jointest b
+id data id data
+
+1 0 1 0
+2 0 2 0
+3 0 3 0
+4 0 4 0
+5 0 5 0
+6 0 6 0
+7 42 7 42
+8 0 8 0
+9 0 9 0
+10 0 10 0
+step c1: COMMIT;
diff --git a/src/test/isolation/specs/eval-plan-qual.spec b/src/test/isolation/specs/eval-plan-qual.spec
index 7ff6f6b8cc9..d2b34ec7cc2 100644
--- a/src/test/isolation/specs/eval-plan-qual.spec
+++ b/src/test/isolation/specs/eval-plan-qual.spec
@@ -21,13 +21,16 @@ setup
CREATE TABLE table_b (id integer, value text);
INSERT INTO table_a VALUES (1, 'tableAValue');
INSERT INTO table_b VALUES (1, 'tableBValue');
+
+ CREATE TABLE jointest AS SELECT generate_series(1,10) AS id, 0 AS data;
+ CREATE INDEX ON jointest(id);
}
teardown
{
DROP TABLE accounts;
DROP TABLE p CASCADE;
- DROP TABLE table_a, table_b;
+ DROP TABLE table_a, table_b, jointest;
}
session "s1"
@@ -78,6 +81,17 @@ step "updateforss" {
UPDATE table_b SET value = 'newTableBValue' WHERE id = 1;
}
+# these tests exercise mark/restore during EPQ recheck, cf bug #15032
+
+step "selectjoinforupdate" {
+ set enable_nestloop to 0;
+ set enable_hashjoin to 0;
+ set enable_seqscan to 0;
+ explain (costs off)
+ select * from jointest a join jointest b on a.id=b.id for update;
+ select * from jointest a join jointest b on a.id=b.id for update;
+}
+
session "s2"
setup { BEGIN ISOLATION LEVEL READ COMMITTED; }
@@ -104,6 +118,7 @@ step "readforss" {
WHERE ta.id = 1 FOR UPDATE OF ta;
}
step "wrtwcte" { UPDATE table_a SET value = 'tableAValue2' WHERE id = 1; }
+step "wrjt" { UPDATE jointest SET data = 42 WHERE id = 7; }
step "c2" { COMMIT; }
session "s3"
@@ -135,3 +150,4 @@ permutation "wx2" "partiallock" "c2" "c1" "read"
permutation "wx2" "lockwithvalues" "c2" "c1" "read"
permutation "updateforss" "readforss" "c1" "c2"
permutation "wrtwcte" "readwcte" "c1" "c2"
+permutation "wrjt" "selectjoinforupdate" "c2" "c1"
generated by cgit v1.2.3 (git 2.25.1) at 2025-07-14 18:32:23 +0000