infoschema: show information about table partitions in information_schema.PARTITIONS

infoschema/tables.go

@@ -1795,12 +1795,19 @@ func dataForPartitions(ctx sessionctx.Context, schemas []*model.DBInfo) ([][]typ
 	createTimeTp := partitionsCols[18].tp
 	for _, schema := range schemas {
 		for _, table := range schema.Tables {
-			if checker != nil && !checker.RequestVerification(ctx.GetSessionVars().ActiveRoles, schema.Name.L, table.Name.L, "", mysql.AllPrivMask) {
+			if checker != nil && !checker.RequestVerification(ctx.GetSessionVars().ActiveRoles, schema.Name.L, table.Name.L, "", mysql.SelectPriv) {
 				continue
 			}
 			createTime := types.NewTime(types.FromGoTime(table.GetUpdateTime()), createTimeTp, types.DefaultFsp)
 
+			var rowCount, dataLength, indexLength uint64
 			if table.GetPartitionInfo() == nil {
+				rowCount = tableRowsMap[table.ID]
+				dataLength, indexLength = getDataAndIndexLength(table, table.ID, rowCount, colLengthMap)
+				avgRowLength := uint64(0)
+				if rowCount != 0 {
+					avgRowLength = dataLength / rowCount
+				}
 				record := types.MakeDatums(
 					catalogVal,    // TABLE_CATALOG
 					schema.Name.O, // TABLE_SCHEMA
@@ -1814,11 +1821,11 @@ func dataForPartitions(ctx sessionctx.Context, schemas []*model.DBInfo) ([][]typ
 					nil,           // PARTITION_EXPRESSION
 					nil,           // SUBPARTITION_EXPRESSION
 					nil,           // PARTITION_DESCRIPTION
-					nil,           // TABLE_ROWS
-					nil,           // AVG_ROW_LENGTH
-					nil,           // DATA_LENGTH
+					rowCount,      // TABLE_ROWS
+					avgRowLength,  // AVG_ROW_LENGTH
+					dataLength,    // DATA_LENGTH
 					nil,           // MAX_DATA_LENGTH
-					nil,           // INDEX_LENGTH
+					indexLength,   // INDEX_LENGTH
 					nil,           // DATA_FREE
 					createTime,    // CREATE_TIME
 					nil,           // UPDATE_TIME
@@ -1830,28 +1837,33 @@ func dataForPartitions(ctx sessionctx.Context, schemas []*model.DBInfo) ([][]typ
 				)
 				rows = append(rows, record)
 			} else {
-				for _, pi := range table.GetPartitionInfo().Definitions {
-					rowCount := tableRowsMap[pi.ID]
-					dataLength, indexLength := getDataAndIndexLength(table, pi.ID, tableRowsMap[pi.ID], colLengthMap)
+				for i, pi := range table.GetPartitionInfo().Definitions {
+					rowCount = tableRowsMap[pi.ID]
+					dataLength, indexLength = getDataAndIndexLength(table, pi.ID, tableRowsMap[pi.ID], colLengthMap)
 
 					avgRowLength := uint64(0)
 					if rowCount != 0 {
 						avgRowLength = dataLength / rowCount
 					}
 
+					var partitionDesc string
+					if table.Partition.Type == 1 {
+						partitionDesc = pi.LessThan[0]
+					}
+
 					record := types.MakeDatums(
 						catalogVal,                    // TABLE_CATALOG
 						schema.Name.O,                 // TABLE_SCHEMA
 						table.Name.O,                  // TABLE_NAME
 						pi.Name.O,                     // PARTITION_NAME
 						nil,                           // SUBPARTITION_NAME
-						nil,                           // PARTITION_ORDINAL_POSITION
+						i+1,                           // PARTITION_ORDINAL_POSITION
 						nil,                           // SUBPARTITION_ORDINAL_POSITION
 						table.Partition.Type.String(), // PARTITION_METHOD
 						nil,                           // SUBPARTITION_METHOD
 						table.Partition.Expr,          // PARTITION_EXPRESSION
 						nil,                           // SUBPARTITION_EXPRESSION
-						nil,                           // PARTITION_DESCRIPTION
+						partitionDesc,                 // PARTITION_DESCRIPTION
 						rowCount,                      // TABLE_ROWS
 						avgRowLength,                  // AVG_ROW_LENGTH
 						dataLength,                    // DATA_LENGTH

infoschema/tables_test.go

@@ -1079,3 +1079,54 @@ func (s *testTableSuite) TestSelectHiddenColumn(c *C) {
 	colInfo[2].Hidden = true
 	tk.MustQuery("select count(*) from INFORMATION_SCHEMA.COLUMNS where table_name = 'hidden'").Check(testkit.Rows("0"))
 }
+
+func (s *testTableSuite) TestPartitionsTable(c *C) {
+	s.dom.SetStatsUpdating(true)
+	oldExpiryTime := infoschema.TableStatsCacheExpiry
+	infoschema.TableStatsCacheExpiry = 0
+	defer func() { infoschema.TableStatsCacheExpiry = oldExpiryTime }()
+
+	do := s.dom
+	h := do.StatsHandle()
+	h.Clear()
+	is := do.InfoSchema()
+
+	tk := testkit.NewTestKit(c, s.store)
+
+	tk.MustExec("USE test;")
+	tk.MustExec("DROP TABLE IF EXISTS `test_partitions`;")
+	tk.MustExec(`CREATE TABLE test_partitions (a int, b int, c varchar(5), primary key(a), index idx(c)) PARTITION BY RANGE (a) (PARTITION p0 VALUES LESS THAN (6), PARTITION p1 VALUES LESS THAN (11), PARTITION p2 VALUES LESS THAN (16));`)
+	h.HandleDDLEvent(<-h.DDLEventCh())
+	tk.MustExec(`insert into test_partitions(a, b, c) values(1, 2, "c"), (7, 3, "d"), (12, 4, "e");`)
+
+	tk.MustQuery("select PARTITION_NAME, PARTITION_DESCRIPTION from information_schema.PARTITIONS where table_name='test_partitions';").Check(
+		testkit.Rows("" +
+			"p0 6]\n" +
+			"[p1 11]\n" +
+			"[p2 16"))
+
+	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.PARTITIONS where table_name='test_partitions';").Check(
+		testkit.Rows("" +
+			"0 0 0 0]\n" +
+			"[0 0 0 0]\n" +
+			"[0 0 0 0"))
+	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
+	c.Assert(h.Update(is), IsNil)
+	tk.MustQuery("select table_rows, avg_row_length, data_length, index_length from information_schema.PARTITIONS where table_name='test_partitions';").Check(
+		testkit.Rows("" +
+			"1 18 18 2]\n" +
+			"[1 18 18 2]\n" +
+			"[1 18 18 2"))
+
+	// Test for table has no partitions.
+	tk.MustExec("DROP TABLE IF EXISTS `test_partitions_1`;")
+	tk.MustExec(`CREATE TABLE test_partitions_1 (a int, b int, c varchar(5), primary key(a), index idx(c));`)
+	h.HandleDDLEvent(<-h.DDLEventCh())
+	tk.MustExec(`insert into test_partitions_1(a, b, c) values(1, 2, "c"), (7, 3, "d"), (12, 4, "e");`)
+	c.Assert(h.DumpStatsDeltaToKV(handle.DumpAll), IsNil)
+	c.Assert(h.Update(is), IsNil)
+	tk.MustQuery("select PARTITION_NAME, TABLE_ROWS, AVG_ROW_LENGTH, DATA_LENGTH, INDEX_LENGTH from information_schema.PARTITIONS where table_name='test_partitions_1';").Check(
+		testkit.Rows("<nil> 3 18 54 6"))
+
+	tk.MustExec("DROP TABLE `test_partitions`;")
+}