table: Avoid encode KindMaxValue of string type (pingcap#31743)

close pingcap#31721
wshwsh12 · Feb 16, 2022 · 2506c86 · 2506c86
1 parent fe635fb
commit 2506c86
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Showing 2 changed files with 33 additions and 15 deletions.
diff --git a/table/tables/partition.go b/table/tables/partition.go
@@ -823,6 +823,8 @@ func (lp *ForListColumnPruning) LocatePartition(sc *stmtctx.StatementContext, v
 
 // LocateRanges locates partition ranges by the column range
 func (lp *ForListColumnPruning) LocateRanges(sc *stmtctx.StatementContext, r *ranger.Range) ([]ListPartitionLocation, error) {
+	var err error
+	var lowKey, highKey []byte
 	lowVal := r.LowVal[0]
 	if r.LowVal[0].Kind() == types.KindMinNotNull {
 		lowVal = types.GetMinValue(lp.ExprCol.GetType())
@@ -831,23 +833,24 @@ func (lp *ForListColumnPruning) LocateRanges(sc *stmtctx.StatementContext, r *ra
 	if r.HighVal[0].Kind() == types.KindMaxValue {
 		highVal = types.GetMaxValue(lp.ExprCol.GetType())
 	}
-	lowKey, err := lp.genKey(sc, lowVal)
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
-	highKey, err := lp.genKey(sc, highVal)
-	if err != nil {
-		return nil, errors.Trace(err)
-	}
 
-	if lp.ExprCol.GetType().EvalType() == types.ETString {
-		// for string type, values returned by GetMinValue and GetMaxValue are already encoded,
-		// so it's unnecessary to invoke genKey to encode them.
-		if r.LowVal[0].Kind() == types.KindMinNotNull {
-			lowKey = (&lowVal).GetBytes()
+	// For string type, values returned by GetMinValue and GetMaxValue are already encoded,
+	// so it's unnecessary to invoke genKey to encode them.
+	if lp.ExprCol.GetType().EvalType() == types.ETString && r.LowVal[0].Kind() == types.KindMinNotNull {
+		lowKey = (&lowVal).GetBytes()
+	} else {
+		lowKey, err = lp.genKey(sc, lowVal)
+		if err != nil {
+			return nil, errors.Trace(err)
 		}
-		if r.HighVal[0].Kind() == types.KindMaxValue {
-			highKey = (&highVal).GetBytes()
+	}
+
+	if lp.ExprCol.GetType().EvalType() == types.ETString && r.HighVal[0].Kind() == types.KindMaxValue {
+		highKey = (&highVal).GetBytes()
+	} else {
+		highKey, err = lp.genKey(sc, highVal)
+		if err != nil {
+			return nil, errors.Trace(err)
 		}
 	}
 

diff --git a/table/tables/partition_test.go b/table/tables/partition_test.go
@@ -608,3 +608,18 @@ func TestIssue24746(t *testing.T) {
 	err = tk.ExecToErr("insert into t_24746 partition (p1) values(4,'ERROR, not allowed to read from partition p0',4) on duplicate key update a = a + 1, b = 'ERROR, not allowed to read from p0!'")
 	require.True(t, table.ErrRowDoesNotMatchGivenPartitionSet.Equal(err))
 }
+
+func TestIssue31721(t *testing.T) {
+	store, clean := testkit.CreateMockStore(t)
+	defer clean()
+	tk := testkit.NewTestKit(t, store)
+	tk.MustExec("use test")
+	tk.MustExec("set tidb_enable_list_partition=on;")
+	tk.MustExec("drop tables if exists t_31721")
+	tk.MustExec("CREATE TABLE `t_31721` (`COL1` char(1) NOT NULL) CHARSET=utf8mb4 COLLATE=utf8mb4_bin PARTITION BY LIST COLUMNS(`COL1`) " +
+		"(PARTITION `P0` VALUES IN ('1')," +
+		"PARTITION `P1` VALUES IN ('2')," +
+		"PARTITION `P2` VALUES IN ('3'));")
+	tk.MustExec("insert into t_31721 values ('1')")
+	tk.MustExec("select * from t_31721 partition(p0, p1) where col1 != 2;")
+}