planner: fix panic of merge join for tables with redundant indexes (#…

…15840) (#15920)
pingcap · Apr 1, 2020 · 5854181 · 5854181
1 parent 340ecb8
commit 5854181
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Showing 2 changed files with 13 additions and 1 deletion.
diff --git a/planner/core/exhaust_physical_plans.go b/planner/core/exhaust_physical_plans.go
@@ -81,7 +81,7 @@ func (p *LogicalJoin) moveEqualToOtherConditions(offsets []int) []expression.Exp
 
 	// Construct otherConds, which is composed of the original other conditions
 	// and the remained unused equal conditions.
-	numOtherConds := len(p.OtherConditions) + len(p.EqualConditions) - len(offsets)
+	numOtherConds := len(p.OtherConditions) + len(p.EqualConditions) - len(usedEqConds)
 	otherConds := make([]expression.Expression, len(p.OtherConditions), numOtherConds)
 	copy(otherConds, p.OtherConditions)
 	for eqCondIdx := range p.EqualConditions {

diff --git a/planner/core/integration_test.go b/planner/core/integration_test.go
@@ -596,3 +596,15 @@ func (s *testIntegrationSuite) TestIssue15546(c *C) {
 	tk.MustExec("create definer='root'@'localhost' view vt(a1, b1) as select a1, b1 from t")
 	tk.MustQuery("select * from pt, vt where a2 = a1").Check(testkit.Rows("1 1 1 1"))
 }
+
+func (s *testIntegrationSuite) TestIssue15813(c *C) {
+	tk := testkit.NewTestKit(c, s.store)
+
+	tk.MustExec("use test")
+	tk.MustExec("drop table if exists t0, t1")
+	tk.MustExec("create table t0(c0 int primary key)")
+	tk.MustExec("create table t1(c0 int primary key)")
+	tk.MustExec("CREATE INDEX i0 ON t0(c0)")
+	tk.MustExec("CREATE INDEX i0 ON t1(c0)")
+	tk.MustQuery("select /*+ MERGE_JOIN(t0, t1) */ * from t0, t1 where t0.c0 = t1.c0").Check(testkit.Rows())
+}