Give notice while converting table type

src/backend/distributed/commands/alter_table.c

@@ -216,6 +216,9 @@ PG_FUNCTION_INFO_V1(alter_distributed_table);
 PG_FUNCTION_INFO_V1(alter_table_set_access_method);
 PG_FUNCTION_INFO_V1(worker_change_sequence_dependency);
 
+/* global variable keeping track of whether we are in a table type conversion function */
+bool InTableTypeConversionFunctionCall = false;
+
 
 /*
  * undistribute_table gets a distributed table name and
@@ -504,10 +507,16 @@ AlterTableSetAccessMethod(TableConversionParameters *params)
  *
  * The function returns a TableConversionReturn object that can stores variables that
  * can be used at the caller operations.
+ *
+ * To be able to provide more meaningful messages while converting a table type,
+ * Citus keeps InTableTypeConversionFunctionCall flag. Don't forget to set it properly
+ * in case you add a new way to return from this function.
  */
 TableConversionReturn *
 ConvertTable(TableConversionState *con)
 {
+	InTableTypeConversionFunctionCall = true;
+
 	/*
 	 * We undistribute citus local tables that are not chained with any reference
 	 * tables via foreign keys at the end of the utility hook.
@@ -536,6 +545,7 @@ ConvertTable(TableConversionState *con)
 		 * subgraph including itself, so return here.
 		 */
 		SetLocalEnableLocalReferenceForeignKeys(oldEnableLocalReferenceForeignKeys);
+		InTableTypeConversionFunctionCall = false;
 		return NULL;
 	}
 	char *newAccessMethod = con->accessMethod ? con->accessMethod :
@@ -820,6 +830,7 @@ ConvertTable(TableConversionState *con)
 
 	SetLocalEnableLocalReferenceForeignKeys(oldEnableLocalReferenceForeignKeys);
 
+	InTableTypeConversionFunctionCall = false;
 	return ret;
 }
 

src/backend/distributed/commands/view.c

@@ -116,6 +116,16 @@ PostprocessViewStmt(Node *node, const char *queryString)
 			return NIL;
 		}
 
+		/*
+		 * Since Citus drops and recreates views while converting a table type, giving a
+		 * NOTICE message is enough if the process in table type conversion function call
+		 */
+		if (InTableTypeConversionFunctionCall)
+		{
+			RaiseDeferredError(errMsg, NOTICE);
+			return NIL;
+		}
+
 		/*
 		 * If the view is already distributed, we should provide an error to not have
 		 * different definition of view on coordinator and worker nodes. If the view

src/backend/distributed/transaction/transaction_management.c

@@ -556,6 +556,7 @@ ResetGlobalVariables()
 	TransactionModifiedNodeMetadata = false;
 	NodeMetadataSyncOnCommit = false;
 	InTopLevelDelegatedFunctionCall = false;
+	InTableTypeConversionFunctionCall = false;
 	ResetWorkerErrorIndication();
 	memset(&AllowedDistributionColumnValue, 0,
 		   sizeof(AllowedDistributionColumn));

src/include/distributed/metadata_utility.h

@@ -41,6 +41,12 @@
 
 #define SHARD_SIZES_COLUMN_COUNT (3)
 
+/*
+ * Flag to keep track of whether the process is currently in a function converting the
+ * type of the table.
+ */
+extern bool InTableTypeConversionFunctionCall;
+
 /* In-memory representation of a typed tuple in pg_dist_shard. */
 typedef struct ShardInterval
 {

src/test/regress/expected/alter_table_set_access_method.out

@@ -607,7 +607,7 @@ DETAIL:  drop cascades to materialized view m_local
 drop cascades to view v_local
 CONTEXT:  SQL statement "DROP TABLE alter_table_set_access_method.local CASCADE"
 NOTICE:  renaming the new table to alter_table_set_access_method.local
-WARNING:  "view v_local" has dependency to "table local" that is not in Citus' metadata
+NOTICE:  "view v_local" has dependency to "table local" that is not in Citus' metadata
 DETAIL:  "view v_local" will be created only locally
 HINT:  Distribute "table local" first to distribute "view v_local"
 CONTEXT:  SQL statement "CREATE VIEW alter_table_set_access_method.v_local AS  SELECT local.a,
@@ -670,7 +670,7 @@ DETAIL:  drop cascades to materialized view m_local
 drop cascades to view v_local
 CONTEXT:  SQL statement "DROP TABLE alter_table_set_access_method.local CASCADE"
 NOTICE:  renaming the new table to alter_table_set_access_method.local
-WARNING:  "view v_local" has dependency to "table local" that is not in Citus' metadata
+NOTICE:  "view v_local" has dependency to "table local" that is not in Citus' metadata
 DETAIL:  "view v_local" will be created only locally
 HINT:  Distribute "table local" first to distribute "view v_local"
 CONTEXT:  SQL statement "CREATE VIEW alter_table_set_access_method.v_local AS  SELECT local.a,

src/test/regress/expected/undistribute_table.out

@@ -340,19 +340,19 @@ drop cascades to view undis_view2
 drop cascades to view another_schema.undis_view3
 CONTEXT:  SQL statement "DROP TABLE undistribute_table.view_table CASCADE"
 NOTICE:  renaming the new table to undistribute_table.view_table
-WARNING:  "view undis_view1" has dependency to "table view_table" that is not in Citus' metadata
+NOTICE:  "view undis_view1" has dependency to "table view_table" that is not in Citus' metadata
 DETAIL:  "view undis_view1" will be created only locally
 HINT:  Distribute "table view_table" first to distribute "view undis_view1"
 CONTEXT:  SQL statement "CREATE VIEW undistribute_table.undis_view1 AS  SELECT view_table.a,
     view_table.b
    FROM view_table;"
-WARNING:  "view undis_view2" has dependency to "table view_table" that is not in Citus' metadata
+NOTICE:  "view undis_view2" has dependency to "table view_table" that is not in Citus' metadata
 DETAIL:  "view undis_view2" will be created only locally
 HINT:  Distribute "table view_table" first to distribute "view undis_view2"
 CONTEXT:  SQL statement "CREATE VIEW undistribute_table.undis_view2 AS  SELECT view_table.a,
     view_table.c
    FROM view_table;"
-WARNING:  "view another_schema.undis_view3" has dependency to "table view_table" that is not in Citus' metadata
+NOTICE:  "view another_schema.undis_view3" has dependency to "table view_table" that is not in Citus' metadata
 DETAIL:  "view another_schema.undis_view3" will be created only locally
 HINT:  Distribute "table view_table" first to distribute "view another_schema.undis_view3"
 CONTEXT:  SQL statement "CREATE VIEW another_schema.undis_view3 AS  SELECT undis_view1.b,