planner: make single partition table support index join on inner side (…

…#19151) (#19197)

Signed-off-by: ti-srebot <ti-srebot@pingcap.com>

executor/index_lookup_merge_join_test.go

@@ -64,3 +64,27 @@ func (s *testSuite9) TestIssue18631(c *C) {
 		"2 2 2 2 2 2 2 2",
 		"1 1 1 1 1 1 1 1"))
 }
+
+func (s *testSuiteAgg) TestIndexJoinOnSinglePartitionTable(c *C) {
+	// For issue 19145
+	tk := testkit.NewTestKitWithInit(c, s.store)
+	tk.MustExec("drop table if exists t1, t2")
+	tk.MustExec("create table t1  (c_int int, c_str varchar(40), primary key (c_int) ) partition by range (c_int) ( partition p0 values less than (10), partition p1 values less than maxvalue )")
+	tk.MustExec("create table t2  (c_int int, c_str varchar(40), primary key (c_int) ) partition by range (c_int) ( partition p0 values less than (10), partition p1 values less than maxvalue )")
+	tk.MustExec("insert into t1 values (1, 'Alice')")
+	tk.MustExec("insert into t2 values (1, 'Bob')")
+	sql := "select /*+ INL_MERGE_JOIN(t1,t2) */ * from t1 join t2 partition(p0) on t1.c_int = t2.c_int and t1.c_str < t2.c_str"
+	tk.MustQuery(sql).Check(testkit.Rows("1 Alice 1 Bob"))
+	rows := s.testData.ConvertRowsToStrings(tk.MustQuery("explain " + sql).Rows())
+	c.Assert(strings.Index(rows[0], "IndexMergeJoin"), Equals, 0)
+
+	sql = "select /*+ INL_HASH_JOIN(t1,t2) */ * from t1 join t2 partition(p0) on t1.c_int = t2.c_int and t1.c_str < t2.c_str"
+	tk.MustQuery(sql).Check(testkit.Rows("1 Alice 1 Bob"))
+	rows = s.testData.ConvertRowsToStrings(tk.MustQuery("explain " + sql).Rows())
+	c.Assert(strings.Index(rows[0], "IndexHashJoin"), Equals, 0)
+
+	sql = "select /*+ INL_JOIN(t1,t2) */ * from t1 join t2 partition(p0) on t1.c_int = t2.c_int and t1.c_str < t2.c_str"
+	tk.MustQuery(sql).Check(testkit.Rows("1 Alice 1 Bob"))
+	rows = s.testData.ConvertRowsToStrings(tk.MustQuery("explain " + sql).Rows())
+	c.Assert(strings.Index(rows[0], "IndexJoin"), Equals, 0)
+}

planner/core/exhaust_physical_plans.go

@@ -757,6 +757,8 @@ func (p *LogicalJoin) constructInnerTableScanTask(
 		rangeDecidedBy:  outerJoinKeys,
 		KeepOrder:       keepOrder,
 		Desc:            desc,
+		physicalTableID: ds.physicalTableID,
+		isPartition:     ds.isPartition,
 	}.Init(ds.ctx, ds.blockOffset)
 	ts.SetSchema(ds.schema.Clone())
 	if rowCount <= 0 {