Attach GPDB 7+ child tables to their root

In GPDB 7+, we no longer have large DDL commands to create a partition
table and its leaf partitions. Each leaf partition must be created
individually (at the moment) and attached to the root or subroot
partition. To do this, we must query for some simple partition
information and construct the SQL command to attach the partition. This
SQL command should be printed immediately after the CREATE TABLE
statement of the leaf partition.

Authored-by: Kevin Yeap <kyeap@vmware.com>

backup/predata_relations.go

@@ -240,6 +240,12 @@ func PrintPostCreateTableStatements(metadataFile *utils.FileWithByteCount, toc *
 				utils.MakeFQN(alteredPartitionRelation.OldSchema, alteredPartitionRelation.Name), alteredPartitionRelation.NewSchema))
 	}
 
+	attachInfo := table.AttachPartitionInfo
+	if (attachInfo != AttachPartitionInfo{}) {
+		statements = append(statements,
+			fmt.Sprintf("ALTER TABLE ONLY %s ATTACH PARTITION %s %s;", attachInfo.Parent, attachInfo.Relname, attachInfo.Expr))
+	}
+
 	PrintStatements(metadataFile, toc, table, statements)
 }
 

backup/queries_table_defs.go

@@ -74,6 +74,7 @@ type TableDefinition struct {
 	PartitionAlteredSchemas []AlteredPartitionRelation
 	AccessMethodName        string
 	PartitionKeyDef         string
+	AttachPartitionInfo     AttachPartitionInfo
 }
 
 /*
@@ -99,6 +100,7 @@ func ConstructDefinitionsForTables(connectionPool *dbconn.DBConn, tableRelations
 	replicaIdentityMap := GetTableReplicaIdentity(connectionPool)
 	partitionAlteredSchemaMap := GetPartitionAlteredSchema(connectionPool)
 	partitionKeyDefs := GetPartitionKeyDefs(connectionPool)
+	attachPartitionInfo := GetAttachPartitionInfo(connectionPool)
 
 	gplog.Verbose("Constructing table definition map")
 	for _, tableRel := range tableRelations {
@@ -121,6 +123,7 @@ func ConstructDefinitionsForTables(connectionPool *dbconn.DBConn, tableRelations
 			PartitionAlteredSchemas: partitionAlteredSchemaMap[oid],
 			AccessMethodName:        accessMethodMap[oid],
 			PartitionKeyDef:         partitionKeyDefs[oid],
+			AttachPartitionInfo:     attachPartitionInfo[oid],
 		}
 		if tableDef.Inherits == nil {
 			tableDef.Inherits = []string{}
@@ -565,11 +568,11 @@ func GetPartitionKeyDefs(connectionPool *dbconn.DBConn) map[uint32]string {
 		return make(map[uint32]string, 0)
 	}
 	query := `
-SELECT
-    partrelid AS oid,
-    pg_get_partkeydef(partrelid) AS keydef
-FROM
-    pg_partitioned_table;`
+	SELECT
+		partrelid AS oid,
+		pg_get_partkeydef(partrelid) AS keydef
+	FROM
+		pg_partitioned_table;`
 
 	var results []struct {
 		Oid    uint32
@@ -584,6 +587,40 @@ FROM
 	return resultMap
 }
 
+type AttachPartitionInfo struct {
+	Oid     uint32
+	Relname string
+	Parent  string
+	Expr    string
+}
+
+func GetAttachPartitionInfo(connectionPool *dbconn.DBConn) map[uint32]AttachPartitionInfo {
+	if connectionPool.Version.Before("7") {
+		return make(map[uint32]AttachPartitionInfo, 0)
+	}
+
+	query := fmt.Sprintf(`
+	SELECT
+		c.oid,
+		quote_ident(n.nspname) || '.' || quote_ident(c.relname) AS relname,
+		quote_ident(rn.nspname) || '.' || quote_ident(rc.relname) AS parent,
+		pg_get_expr(c.relpartbound, c.oid) AS expr
+	FROM pg_class c
+		JOIN pg_namespace n ON c.relnamespace = n.oid
+		JOIN pg_class rc ON pg_partition_root(c.oid) = rc.oid
+		JOIN pg_namespace rn ON rc.relnamespace = rn.oid
+	WHERE c.relispartition = 't'`)
+
+	results := make([]AttachPartitionInfo, 0)
+	err := connectionPool.Select(&results, query)
+	gplog.FatalOnError(err)
+	resultMap := make(map[uint32]AttachPartitionInfo)
+	for _, result := range results {
+		resultMap[result.Oid] = result
+	}
+	return resultMap
+}
+
 func selectAsOidToStringMap(connectionPool *dbconn.DBConn, query string) map[uint32]string {
 	var results []struct {
 		Oid   uint32

integration/predata_relations_create_test.go

@@ -432,6 +432,36 @@ SET SUBPARTITION TEMPLATE ` + `
 			resultTable := backup.ConstructDefinitionsForTables(connectionPool, []backup.Relation{testTable.Relation})[0]
 			Expect(resultTable.ReplicaIdentity).To(Equal("f"))
 		})
+		It("prints a GPDB 7+ ALTER statement to ATTACH a child table to it's root", func() {
+			testutils.SkipIfBefore7(connectionPool)
+			testhelper.AssertQueryRuns(connectionPool, "CREATE TABLE public.testroottable(i int) PARTITION BY RANGE (i) DISTRIBUTED BY (i); ")
+			defer testhelper.AssertQueryRuns(connectionPool, "DROP TABLE public.testroottable;")
+			testhelper.AssertQueryRuns(connectionPool, "CREATE TABLE public.testchildtable(i int) DISTRIBUTED BY (i);")
+			defer testhelper.AssertQueryRuns(connectionPool, "DROP TABLE public.testchildtable;")
+			tableMetadata = backup.ObjectMetadata{Privileges: []backup.ACL{}, ObjectType: "RELATION"}
+			testChildTable := backup.Table{
+				Relation: backup.Relation{Schema: "public", Name: "testChildTable"},
+				TableDefinition: backup.TableDefinition{
+					DistPolicy:  "DISTRIBUTED BY (i)",
+					ColumnDefs:  []backup.ColumnDefinition{tableRow},
+					ExtTableDef: extTableEmpty,
+					Inherits:    []string{},
+					AttachPartitionInfo: backup.AttachPartitionInfo{
+						Relname: "public.testchildtable",
+						Parent:  "public.testroottable",
+						Expr:    "FOR VALUES FROM (1) TO (2)",
+					},
+				},
+			}
+
+			backup.PrintPostCreateTableStatements(backupfile, tocfile, testChildTable, tableMetadata)
+			testhelper.AssertQueryRuns(connectionPool, buffer.String())
+
+			attachPartitionInfoMap := backup.GetAttachPartitionInfo(connectionPool)
+			childTableOid := testutils.OidFromObjectName(connectionPool, "public", "testchildtable", backup.TYPE_RELATION)
+			testChildTable.AttachPartitionInfo.Oid = childTableOid
+			structmatcher.ExpectStructsToMatch(&testChildTable.AttachPartitionInfo, attachPartitionInfoMap[childTableOid])
+		})
 	})
 	Describe("PrintCreateViewStatements", func() {
 		var viewDef sql.NullString

integration/predata_table_defs_queries_test.go

@@ -878,4 +878,22 @@ SET SUBPARTITION TEMPLATE
 			Expect(result[oid]).To(ConsistOf(expectedAlteredPartitions))
 		})
 	})
+	Describe("GetAttachedPartitionInfo", func() {
+		It("Returns a map of table oid to attach partition info", func() {
+			testutils.SkipIfBefore7(connectionPool)
+			testhelper.AssertQueryRuns(connectionPool, "CREATE SCHEMA testschema")
+			defer testhelper.AssertQueryRuns(connectionPool, "DROP SCHEMA testschema")
+			testhelper.AssertQueryRuns(connectionPool, "CREATE TABLE testschema.foopart(a integer, b integer) PARTITION BY RANGE (b) DISTRIBUTED BY (a)")
+			testhelper.AssertQueryRuns(connectionPool, "CREATE TABLE testschema.foopart_1_prt_1 (a integer, b integer) DISTRIBUTED BY (a)")
+			testhelper.AssertQueryRuns(connectionPool, "ALTER TABLE ONLY testschema.foopart ATTACH PARTITION testschema.foopart_1_prt_1 FOR VALUES FROM (1) TO (2)")
+			defer testhelper.AssertQueryRuns(connectionPool, "DROP TABLE testschema.foopart")
+
+			oid := testutils.OidFromObjectName(connectionPool, "testschema", "foopart_1_prt_1", backup.TYPE_RELATION)
+			result := backup.GetAttachPartitionInfo(connectionPool)
+
+			expectedAttachPartitionInfo := backup.AttachPartitionInfo{Oid: oid, Relname: "testschema.foopart_1_prt_1", Parent: "testschema.foopart", Expr: "FOR VALUES FROM (1) TO (2)"}
+
+			structmatcher.ExpectStructsToMatch(result[oid], &expectedAttachPartitionInfo)
+		})
+	})
 })