fix(relations): Ensure materialized view access method is restored

On Cloudberry, Greenplum 7+, materialized views must be created with
a specific access method (e.g., 'heap', 'ao_row') and associated storage
options in the 'WITH' clause (e.g., 'compresstype=zstd').

The prior implementation did not back up the 'USING' clause.
During restore, the database would default to another access method
(e.g., 'heap') which might not support the view's storage options.
This incompatibility caused the 'CREATE MATERIALIZED VIEW' command
to fail validation.

This commit corrects the failure by:
- Updating the view query for Cloudberry, GPDB 7+ to fetch the access method.
- Modifying DDL generation to include the 'USING' clause.
- Updating integration tests to verify the fix.

Fixes #61

Author: robertmu

backup/predata_relations.go

@@ -444,8 +444,12 @@ func PrintCreateViewStatement(metadataFile *utils.FileWithByteCount, objToc *toc
 	if !view.IsMaterialized {
 		metadataFile.MustPrintf("\n\nCREATE VIEW %s%s AS %s\n", view.FQN(), view.Options, view.Definition.String)
 	} else {
-		metadataFile.MustPrintf("\n\nCREATE MATERIALIZED VIEW %s%s%s AS %s\nWITH NO DATA\n%s;\n",
-			view.FQN(), view.Options, tablespaceClause, view.Definition.String[:len(view.Definition.String)-1], view.DistPolicy.Policy)
+		accessMethodClause := ""
+		if view.AccessMethodName != "" {
+			accessMethodClause = fmt.Sprintf(" USING %s", view.AccessMethodName)
+		}
+		metadataFile.MustPrintf("\n\nCREATE MATERIALIZED VIEW %s%s%s%s AS %s\nWITH NO DATA\n%s;\n",
+			view.FQN(), accessMethodClause, view.Options, tablespaceClause, view.Definition.String[:len(view.Definition.String)-1], view.DistPolicy.Policy)
 	}
 	section, entry := view.GetMetadataEntry()
 	tier := globalTierMap[view.GetUniqueID()]

backup/queries_relations.go

@@ -344,16 +344,17 @@ func GetSequenceDefinition(connectionPool *dbconn.DBConn, seqName string) Sequen
 }
 
 type View struct {
-	Oid            uint32
-	Schema         string
-	Name           string
-	Options        string
-	Definition     sql.NullString
-	Tablespace     string
-	IsMaterialized bool
-	DistPolicy     DistPolicy
-	NeedsDummy     bool
-	ColumnDefs     []ColumnDefinition
+	Oid              uint32
+	Schema           string
+	Name             string
+	Options          string
+	Definition       sql.NullString
+	Tablespace       string
+	IsMaterialized   bool
+	DistPolicy       DistPolicy
+	NeedsDummy       bool
+	ColumnDefs       []ColumnDefinition
+	AccessMethodName string
 }
 
 func (v View) GetMetadataEntry() (string, toc.MetadataEntry) {
@@ -412,7 +413,7 @@ func GetAllViews(connectionPool *dbconn.DBConn) []View {
 
 	// Materialized views were introduced in GPDB 7 and backported to GPDB 6.2.
 	// Reloptions and tablespace added to pg_class in GPDB 6
-	atLeast6Query := fmt.Sprintf(`
+	version6Query := fmt.Sprintf(`
 	SELECT
 		c.oid AS oid,
 		quote_ident(n.nspname) AS schema,
@@ -428,11 +429,31 @@ func GetAllViews(connectionPool *dbconn.DBConn) []View {
 		AND %s
 		AND %s`, relationAndSchemaFilterClause(), ExtensionFilterClause("c"))
 
+	atLeast7Query := fmt.Sprintf(`
+	SELECT
+		c.oid AS oid,
+		quote_ident(n.nspname) AS schema,
+		quote_ident(c.relname) AS name,
+		pg_get_viewdef(c.oid) AS definition,
+		coalesce(' WITH (' || array_to_string(c.reloptions, ', ') || ')', '') AS options,
+		coalesce(quote_ident(t.spcname), '') AS tablespace,
+		c.relkind='m' AS ismaterialized,
+		coalesce(quote_ident(am.amname), '') AS accessmethodname
+	FROM pg_class c
+		LEFT JOIN pg_namespace n ON n.oid = c.relnamespace
+		LEFT JOIN pg_tablespace t ON t.oid = c.reltablespace
+		LEFT JOIN pg_am am ON am.oid = c.relam
+	WHERE c.relkind IN ('m', 'v')
+		AND %s
+		AND %s`, relationAndSchemaFilterClause(), ExtensionFilterClause("c"))
+
 	query := ""
 	if connectionPool.Version.IsGPDB() && connectionPool.Version.Before("6") {
 		query = before6Query
+	} else if connectionPool.Version.IsGPDB() && connectionPool.Version.Is("6") {
+		query = version6Query
 	} else {
-		query = atLeast6Query
+		query = atLeast7Query
 	}
 
 	results := make([]View, 0)

integration/predata_relations_create_test.go

@@ -576,6 +576,9 @@ SET SUBPARTITION TEMPLATE ` + `
 		})
 		It("creates a view with privileges, owner, security label, and comment", func() {
 			view := backup.View{Oid: 1, Schema: "public", Name: "simplemview", Definition: sql.NullString{String: " SELECT 1 AS a;", Valid: true}, IsMaterialized: true, DistPolicy: backup.DistPolicy{Policy: "DISTRIBUTED BY (a)"}}
+			if (connectionPool.Version.IsGPDB() && connectionPool.Version.AtLeast("7")) || connectionPool.Version.IsCBDB() {
+				view.AccessMethodName = "heap"
+			}
 			viewMetadata := testutils.DefaultMetadata(toc.OBJ_MATERIALIZED_VIEW, true, true, true, includeSecurityLabels)
 
 			backup.PrintCreateViewStatement(backupfile, tocfile, view, viewMetadata)
@@ -594,7 +597,9 @@ SET SUBPARTITION TEMPLATE ` + `
 		})
 		It("creates a materialized view with options", func() {
 			view := backup.View{Oid: 1, Schema: "public", Name: "simplemview", Options: " WITH (fillfactor=10)", Definition: sql.NullString{String: " SELECT 1 AS a;", Valid: true}, IsMaterialized: true, DistPolicy: backup.DistPolicy{Policy: "DISTRIBUTED BY (a)"}}
-
+			if (connectionPool.Version.IsGPDB() && connectionPool.Version.AtLeast("7")) || connectionPool.Version.IsCBDB() {
+				view.AccessMethodName = "heap"
+			}
 			backup.PrintCreateViewStatement(backupfile, tocfile, view, backup.ObjectMetadata{})
 
 			testhelper.AssertQueryRuns(connectionPool, buffer.String())

integration/predata_relations_queries_test.go

@@ -512,6 +512,9 @@ PARTITION BY LIST (gender)
 
 			results := backup.GetAllViews(connectionPool)
 			materialView := backup.View{Oid: 1, Schema: "public", Name: "simplematerialview", Definition: sql.NullString{String: " SELECT 1 AS a;", Valid: true}, IsMaterialized: true, DistPolicy: backup.DistPolicy{Policy: "DISTRIBUTED BY (a)"}}
+			if (connectionPool.Version.IsGPDB() && connectionPool.Version.AtLeast("7")) || connectionPool.Version.IsCBDB() {
+				materialView.AccessMethodName = "heap"
+			}
 
 			materialView.Oid = testutils.OidFromObjectName(connectionPool, "public", "simplematerialview", backup.TYPE_RELATION)
 			Expect(results).To(HaveLen(1))
@@ -526,7 +529,9 @@ PARTITION BY LIST (gender)
 
 			results := backup.GetAllViews(connectionPool)
 			materialView := backup.View{Oid: 1, Schema: "public", Name: "simplematerialview", Definition: sql.NullString{String: " SELECT 1 AS a;", Valid: true}, Options: " WITH (fillfactor=50, autovacuum_enabled=false)", IsMaterialized: true, DistPolicy: backup.DistPolicy{Policy: "DISTRIBUTED BY (a)"}}
-
+			if (connectionPool.Version.IsGPDB() && connectionPool.Version.AtLeast("7")) || connectionPool.Version.IsCBDB() {
+				materialView.AccessMethodName = "heap"
+			}
 			materialView.Oid = testutils.OidFromObjectName(connectionPool, "public", "simplematerialview", backup.TYPE_RELATION)
 			Expect(results).To(HaveLen(1))
 			structmatcher.ExpectStructsToMatchExcluding(&materialView, &results[0], "ColumnDefs", "DistPolicy.Oid")
@@ -542,7 +547,9 @@ PARTITION BY LIST (gender)
 
 			results := backup.GetAllViews(connectionPool)
 			materialView := backup.View{Oid: 1, Schema: "public", Name: "simplematerialview", Definition: sql.NullString{String: " SELECT 1 AS a;", Valid: true}, Tablespace: "test_tablespace", IsMaterialized: true, DistPolicy: backup.DistPolicy{Policy: "DISTRIBUTED BY (a)"}}
-
+			if (connectionPool.Version.IsGPDB() && connectionPool.Version.AtLeast("7")) || connectionPool.Version.IsCBDB() {
+				materialView.AccessMethodName = "heap"
+			}
 			Expect(results).To(HaveLen(1))
 			structmatcher.ExpectStructsToMatchExcluding(&materialView, &results[0], "Oid", "ColumnDefs", "DistPolicy.Oid")
 		})