planner: missed order by item for index merge sometimes (#46576)

planner/core/find_best_task.go

@@ -1209,6 +1209,13 @@ func (ds *DataSource) convertToPartialIndexScan(prop *property.PhysicalProperty,
 	is := ds.getOriginalPhysicalIndexScan(prop, path, false, false)
 	// TODO: Consider using isIndexCoveringColumns() to avoid another TableRead
 	indexConds := path.IndexFilters
+	if matchProp {
+		if is.Table.GetPartitionInfo() != nil && !is.Index.Global && is.SCtx().GetSessionVars().StmtCtx.UseDynamicPartitionPrune() {
+			is.Columns, is.schema, _ = AddExtraPhysTblIDColumn(is.SCtx(), is.Columns, is.schema)
+		}
+		// Add sort items for index scan for merge-sort operation between partitions.
+		is.ByItems = byItems
+	}
 	if len(indexConds) > 0 {
 		var selectivity float64
 		if path.CountAfterAccess > 0 {
@@ -1249,6 +1256,12 @@ func (ds *DataSource) convertToPartialTableScan(prop *property.PhysicalProperty,
 		}
 	}
 	ts.filterCondition = newFilterConds
+	if matchProp {
+		if ts.Table.GetPartitionInfo() != nil && ts.SCtx().GetSessionVars().StmtCtx.UseDynamicPartitionPrune() {
+			ts.Columns, ts.schema, _ = AddExtraPhysTblIDColumn(ts.SCtx(), ts.Columns, ts.schema)
+		}
+		ts.ByItems = byItems
+	}
 	if len(ts.filterCondition) > 0 {
 		selectivity, _, err := ds.tableStats.HistColl.Selectivity(ds.ctx, ts.filterCondition, nil)
 		if err != nil {

planner/core/issuetest/BUILD.bazel

@@ -5,6 +5,6 @@ go_test(
     timeout = "short",
     srcs = ["planner_issue_test.go"],
     flaky = True,
-    shard_count = 5,
+    shard_count = 6,
     deps = ["//testkit"],
 )

planner/core/issuetest/planner_issue_test.go

@@ -107,3 +107,17 @@ func TestIssue45036(t *testing.T) {
 		"    └─TableReader_9 10000.00 root partition:all data:TableRangeScan_8",
 		"      └─TableRangeScan_8 10000.00 cop[tikv] table:s range:[1,100000], keep order:false, stats:pseudo"))
 }
+
+func TestIssue46005(t *testing.T) {
+	store := testkit.CreateMockStore(t)
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("create table tbl_39(col_239 year(4) not null default '2009', primary key(col_239), unique key idx_223(col_239), key idx_224(col_239))")
+	tk.MustExec("insert into tbl_39 values (1994),(1995),(1996),(1997)")
+	tk.HasPlan(
+		"select  /*+ use_index_merge( tbl_39) */ col_239  from tbl_39 where not( tbl_39.col_239 not in ( '1994' ) ) and tbl_39.col_239 not in ( '2004' , '2010' , '2010' ) or not( tbl_39.col_239 <= '1996' ) and not( tbl_39.col_239 between '2026' and '2011' ) order by tbl_39.col_239 limit 382",
+		"IndexMerge",
+	)
+	rs := tk.MustQuery("select  /*+ use_index_merge( tbl_39) */ col_239  from tbl_39 where not( tbl_39.col_239 not in ( '1994' ) ) and tbl_39.col_239 not in ( '2004' , '2010' , '2010' ) or not( tbl_39.col_239 <= '1996' ) and not( tbl_39.col_239 between '2026' and '2011' ) order by tbl_39.col_239 limit 382")
+	rs.Check(testkit.Rows("1994", "1997"))
+}