3 files changed, 58 insertions, 0 deletions
diff --git a/src/test/isolation/expected/predicate-lock-hot-tuple.out b/src/test/isolation/expected/predicate-lock-hot-tuple.out
new file mode 100644
index 00000000000..d1c69bbbd03
--- /dev/null
+++ b/src/test/isolation/expected/predicate-lock-hot-tuple.out
@@ -0,0 +1,20 @@
+Parsed test spec with 2 sessions
+
+starting permutation: b1 b2 r1 r2 w1 w2 c1 c2
+step b1: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step b2: BEGIN ISOLATION LEVEL SERIALIZABLE;
+step r1: SELECT * FROM test WHERE i IN (5, 7)
+i              t              
+
+5              apple          
+7              pear_hot_updated
+step r2: SELECT * FROM test WHERE i IN (5, 7)
+i              t              
+
+5              apple          
+7              pear_hot_updated
+step w1: UPDATE test SET t = 'pear_xact1' WHERE i = 7
+step w2: UPDATE test SET t = 'apple_xact2' WHERE i = 5
+step c1: COMMIT;
+step c2: COMMIT;
+ERROR:  could not serialize access due to read/write dependencies among transactions
diff --git a/src/test/isolation/isolation_schedule b/src/test/isolation/isolation_schedule
index 74b50779e25..d6481f6471e 100644
--- a/src/test/isolation/isolation_schedule
+++ b/src/test/isolation/isolation_schedule
@@ -17,6 +17,7 @@ test: partial-index
 test: two-ids
 test: multiple-row-versions
 test: index-only-scan
+test: predicate-lock-hot-tuple
 test: deadlock-simple
 test: deadlock-hard
 test: deadlock-soft
diff --git a/src/test/isolation/specs/predicate-lock-hot-tuple.spec b/src/test/isolation/specs/predicate-lock-hot-tuple.spec
new file mode 100644
index 00000000000..d16fb60533b
--- /dev/null
+++ b/src/test/isolation/specs/predicate-lock-hot-tuple.spec
@@ -0,0 +1,37 @@
+# Test predicate locks on HOT updated tuples.
+#
+# This test has two serializable transactions. Both select two rows
+# from the table, and then update one of them.
+# If these were serialized (run one at a time), the transaction that
+# runs later would see one of the rows to be updated.
+#
+# Any overlap between the transactions must cause a serialization failure.
+# We used to have a bug in predicate locking HOT updated tuples, which
+# caused the conflict to be missed, if the row was HOT updated.
+
+setup
+{
+  CREATE TABLE test (i int PRIMARY KEY, t text);
+  INSERT INTO test VALUES (5, 'apple'), (7, 'pear'), (11, 'banana');
+  -- HOT-update 'pear' row.
+  UPDATE test SET t = 'pear_hot_updated' WHERE i = 7;
+}
+
+teardown
+{
+  DROP TABLE test;
+}
+
+session "s1"
+step "b1" { BEGIN ISOLATION LEVEL SERIALIZABLE; }
+step "r1" { SELECT * FROM test WHERE i IN (5, 7) }
+step "w1" { UPDATE test SET t = 'pear_xact1' WHERE i = 7 }
+step "c1" { COMMIT; }
+
+session "s2"
+step "b2" { BEGIN ISOLATION LEVEL SERIALIZABLE; }
+step "r2" { SELECT * FROM test WHERE i IN (5, 7) }
+step "w2" { UPDATE test SET t = 'apple_xact2' WHERE i = 5 }
+step "c2" { COMMIT; }
+
+permutation "b1" "b2" "r1" "r2" "w1" "w2" "c1" "c2"