ddl: let partition table pre split index regions (pingcap#59547)

close pingcap#59530

Author: Defined2014

pkg/ddl/split_region.go

@@ -33,15 +33,20 @@ import (
 
 func splitPartitionTableRegion(ctx sessionctx.Context, store kv.SplittableStore, tbInfo *model.TableInfo, parts []model.PartitionDefinition, scatterScope string) {
 	// Max partition count is 8192, should we sample and just choose some partitions to split?
-	regionIDs := make([]uint64, 0, len(parts))
+	var regionIDs []uint64
 	ctxWithTimeout, cancel := context.WithTimeout(context.Background(), ctx.GetSessionVars().GetSplitRegionTimeout())
 	defer cancel()
 	ctxWithTimeout = kv.WithInternalSourceType(ctxWithTimeout, kv.InternalTxnDDL)
 	if shardingBits(tbInfo) > 0 && tbInfo.PreSplitRegions > 0 {
+		regionIDs = make([]uint64, 0, len(parts)*(len(tbInfo.Indices)+1))
+		scatter, tableID := getScatterConfig(scatterScope, tbInfo.ID)
+		// Try to split global index region here.
+		regionIDs = append(regionIDs, splitIndexRegion(store, tbInfo, scatter, tableID)...)
 		for _, def := range parts {
 			regionIDs = append(regionIDs, preSplitPhysicalTableByShardRowID(ctxWithTimeout, store, tbInfo, def.ID, scatterScope)...)
 		}
 	} else {
+		regionIDs = make([]uint64, 0, len(parts))
 		for _, def := range parts {
 			regionIDs = append(regionIDs, SplitRecordRegion(ctxWithTimeout, store, def.ID, tbInfo.ID, scatterScope))
 		}
@@ -127,7 +132,7 @@ func preSplitPhysicalTableByShardRowID(ctx context.Context, store kv.SplittableS
 		logutil.DDLLogger().Warn("pre split some table regions failed",
 			zap.Stringer("table", tbInfo.Name), zap.Int("successful region count", len(regionIDs)), zap.Error(err))
 	}
-	regionIDs = append(regionIDs, splitIndexRegion(store, tbInfo, scatter, &tableID)...)
+	regionIDs = append(regionIDs, splitIndexRegion(store, tbInfo, scatter, physicalID)...)
 	return regionIDs
 }
 
@@ -146,13 +151,32 @@ func SplitRecordRegion(ctx context.Context, store kv.SplittableStore, physicalTa
 	return 0
 }
 
-func splitIndexRegion(store kv.SplittableStore, tblInfo *model.TableInfo, scatter bool, tableID *int64) []uint64 {
+func splitIndexRegion(store kv.SplittableStore, tblInfo *model.TableInfo, scatter bool, physicalTableID int64) []uint64 {
 	splitKeys := make([][]byte, 0, len(tblInfo.Indices))
 	for _, idx := range tblInfo.Indices {
-		indexPrefix := tablecodec.EncodeTableIndexPrefix(tblInfo.ID, idx.ID)
+		if tblInfo.GetPartitionInfo() != nil &&
+			((idx.Global && tblInfo.ID != physicalTableID) || (!idx.Global && tblInfo.ID == physicalTableID)) {
+			continue
+		}
+		id := idx.ID
+		// For normal index, split regions like
+		// [t_tid_, 			t_tid_i_idx1ID+1),
+		// [t_tid_i_idx1ID+1,	t_tid_i_idx2ID+1),
+		// ...
+		// [t_tid_i_idxMaxID+1, t_tid_r_xxxx)
+		//
+		// For global index, split regions like
+		// [t_tid_i_idx1ID, t_tid_i_idx2ID),
+		// [t_tid_i_idx2ID, t_tid_i_idx3ID),
+		// ...
+		// [t_tid_i_idxMaxID, t_pid1_)
+		if !idx.Global {
+			id = id + 1
+		}
+		indexPrefix := tablecodec.EncodeTableIndexPrefix(physicalTableID, id)
 		splitKeys = append(splitKeys, indexPrefix)
 	}
-	regionIDs, err := store.SplitRegions(context.Background(), splitKeys, scatter, tableID)
+	regionIDs, err := store.SplitRegions(context.Background(), splitKeys, scatter, &physicalTableID)
 	if err != nil {
 		logutil.DDLLogger().Warn("pre split some table index regions failed",
 			zap.Stringer("table", tblInfo.Name), zap.Int("successful region count", len(regionIDs)), zap.Error(err))

pkg/ddl/tests/partition/db_partition_test.go

@@ -1232,11 +1232,11 @@ func TestAlterTableTruncatePartitionPreSplitRegion(t *testing.T) {
 		PARTITION p3 VALUES LESS THAN (MAXVALUE))`)
 	re = tk.MustQuery("show table t2 regions")
 	rows = re.Rows()
-	require.Len(t, rows, 24)
+	require.Len(t, rows, 27)
 	tk.MustExec(`alter table t2 truncate partition p3`)
 	re = tk.MustQuery("show table t2 regions")
 	rows = re.Rows()
-	require.Len(t, rows, 24)
+	require.Len(t, rows, 27)
 }
 
 func TestCreateTableWithKeyPartition(t *testing.T) {

pkg/executor/test/splittest/split_table_test.go

@@ -575,6 +575,29 @@ func TestShowTableRegion(t *testing.T) {
 		}
 		require.Equal(t, infosync.PlacementScheduleStatePending.String(), rows[i][12])
 	}
+
+	tk.MustExec("drop table if exists sbtest0000")
+	tk.MustExec("CREATE TABLE sbtest0000(" +
+		"  id bigint," +
+		"  k bigint DEFAULT '0' NOT NULL," +
+		"  c CHAR(120) DEFAULT '' NOT NULL," +
+		"  pad CHAR(60) DEFAULT '' NOT NULL," +
+		"  UNIQUE KEY uk(id) GLOBAL," +
+		"  key idx0(k,c)," +
+		"  key idx1(c))SHARD_ROW_ID_BITS=3 PRE_SPLIT_REGIONS=2 " +
+		"PARTITION BY RANGE(id)(PARTITION p VALUES LESS THAN (MAXVALUE))")
+	re = tk.MustQuery("show table sbtest0000 regions")
+	rows = re.Rows()
+	require.Len(t, rows, 7) // 3 index regions + 4 record regions
+
+	tbl = external.GetTableByName(t, tk, "test", "sbtest0000")
+	require.Equal(t, fmt.Sprintf("t_%d_i_1_", tbl.Meta().ID), rows[0][1]) // index `uk``
+	require.Equal(t, fmt.Sprintf("t_%d_i_4_", tbl.Meta().ID+1), rows[1][1])
+	require.Regexp(t, fmt.Sprintf("t_%d_r_.*", tbl.Meta().ID+1), rows[2][1])
+	require.Regexp(t, fmt.Sprintf("t_%d_r_.*", tbl.Meta().ID+1), rows[3][1])
+	require.Regexp(t, fmt.Sprintf("t_%d_r_.*", tbl.Meta().ID+1), rows[4][1])
+	require.Equal(t, fmt.Sprintf("t_%d_", tbl.Meta().ID+1), rows[5][1])     // index `idx0`
+	require.Equal(t, fmt.Sprintf("t_%d_i_3_", tbl.Meta().ID+1), rows[6][1]) // index `idx1`
 }
 
 func BenchmarkLocateRegion(t *testing.B) {