Merge pull request #1312 from citusdata/rename_support

Enable distributed ALTER TABLE ... RENAME COLUMN

cr: @byucesoy

src/backend/distributed/executor/multi_utility.c

@@ -112,6 +112,7 @@ static List * PlanDropIndexStmt(DropStmt *dropIndexStatement,
 								const char *dropIndexCommand);
 static List * PlanAlterTableStmt(AlterTableStmt *alterTableStatement,
 								 const char *alterTableCommand);
+static List * PlanRenameStmt(RenameStmt *renameStmt, const char *renameCommand);
 static Node * WorkerProcessAlterTableStmt(AlterTableStmt *alterTableStatement,
 										  const char *alterTableCommand);
 static List * PlanAlterObjectSchemaStmt(AlterObjectSchemaStmt *alterObjectSchemaStmt,
@@ -132,12 +133,12 @@ static void ErrorIfUnsupportedSeqStmt(CreateSeqStmt *createSeqStmt);
 static void ErrorIfDistributedAlterSeqOwnedBy(AlterSeqStmt *alterSeqStmt);
 static void ErrorIfUnsupportedTruncateStmt(TruncateStmt *truncateStatement);
 static bool OptionsSpecifyOwnedBy(List *optionList, Oid *ownedByTableId);
-static void ErrorIfDistributedRenameStmt(RenameStmt *renameStatement);
+static void ErrorIfUnsupportedRenameStmt(RenameStmt *renameStmt);
 
 /* Local functions forward declarations for helper functions */
 static char * ExtractNewExtensionVersion(Node *parsetree);
 static void CreateLocalTable(RangeVar *relation, char *nodeName, int32 nodePort);
-static bool IsAlterTableRenameStmt(RenameStmt *renameStatement);
+static bool IsAlterTableRenameStmt(RenameStmt *renameStmt);
 static void ExecuteDistributedDDLJob(DDLJob *ddlJob);
 static void ShowNoticeIfNotUsing2PC(void);
 static List * DDLTaskList(Oid relationId, const char *commandString);
@@ -290,11 +291,7 @@ multi_ProcessUtility(Node *parsetree,
 		 */
 		if (IsA(parsetree, RenameStmt))
 		{
-			RenameStmt *renameStmt = (RenameStmt *) parsetree;
+			ddlJobs = PlanRenameStmt((RenameStmt *) parsetree, queryString);
-			if (IsAlterTableRenameStmt(renameStmt))
-			{
-				ErrorIfDistributedRenameStmt(renameStmt);
-			}
 		}
 
 		/*
@@ -981,6 +978,61 @@ PlanAlterTableStmt(AlterTableStmt *alterTableStatement, const char *alterTableCo
 }
 
 
+/*
+ * PlanRenameStmt first determines whether a given rename statement involves
+ * a distributed table. If so (and if it is supported, i.e. renames a column),
+ * it creates a DDLJob to encapsulate information needed during the worker node
+ * portion of DDL execution before returning that DDLJob in a List. If no dis-
+ * tributed table is involved, this function returns NIL.
+ */
+static List *
+PlanRenameStmt(RenameStmt *renameStmt, const char *renameCommand)
+{
+	Oid relationId = InvalidOid;
+	bool isDistributedRelation = false;
+	DDLJob *ddlJob = NULL;
+
+	if (!IsAlterTableRenameStmt(renameStmt))
+	{
+		return NIL;
+	}
+
+	/*
+	 * The lock levels here should be same as the ones taken in
+	 * RenameRelation(), renameatt() and RenameConstraint(). However, since all
+	 * three statements have identical lock levels, we just use a single statement.
+	 */
+	relationId = RangeVarGetRelid(renameStmt->relation, AccessExclusiveLock,
+								  renameStmt->missing_ok);
+
+	/*
+	 * If the table does not exist, don't do anything here to allow PostgreSQL
+	 * to throw the appropriate error or notice message later.
+	 */
+	if (!OidIsValid(relationId))
+	{
+		return NIL;
+	}
+
+	/* we have no planning to do unless the table is distributed */
+	isDistributedRelation = IsDistributedTable(relationId);
+	if (!isDistributedRelation)
+	{
+		return NIL;
+	}
+
+	ErrorIfUnsupportedRenameStmt(renameStmt);
+
+	ddlJob = palloc0(sizeof(DDLJob));
+	ddlJob->targetRelationId = relationId;
+	ddlJob->concurrentIndexCmd = false;
+	ddlJob->commandString = renameCommand;
+	ddlJob->taskList = DDLTaskList(relationId, renameCommand);
+
+	return list_make1(ddlJob);
+}
+
+
 /*
  * WorkerProcessAlterTableStmt checks and processes the alter table statement to be
  * worked on the distributed table of the worker node. Currently, it only processes
@@ -1980,40 +2032,24 @@ OptionsSpecifyOwnedBy(List *optionList, Oid *ownedByTableId)
 
 /*
  * ErrorIfDistributedRenameStmt errors out if the corresponding rename statement
- * operates on a distributed table or its objects.
+ * operates on any part of a distributed table other than a column.
  *
  * Note: This function handles only those rename statements which operate on tables.
  */
 static void
-ErrorIfDistributedRenameStmt(RenameStmt *renameStatement)
+ErrorIfUnsupportedRenameStmt(RenameStmt *renameStmt)
 {
-	Oid relationId = InvalidOid;
+	Assert(IsAlterTableRenameStmt(renameStmt));
-	bool isDistributedRelation = false;
 
-	Assert(IsAlterTableRenameStmt(renameStatement));
+	if (renameStmt->renameType == OBJECT_TABLE)
-
-	/*
-	 * The lock levels here should be same as the ones taken in
-	 * RenameRelation(), renameatt() and RenameConstraint(). However, since all
-	 * three statements have identical lock levels, we just use a single statement.
-	 */
-	relationId = RangeVarGetRelid(renameStatement->relation, AccessExclusiveLock,
-								  renameStatement->missing_ok);
-
-	/*
-	 * If the table does not exist, we don't do anything here, and allow postgres to
-	 * throw the appropriate error or notice message later.
-	 */
-	if (!OidIsValid(relationId))
-	{
-		return;
-	}
-
-	isDistributedRelation = IsDistributedTable(relationId);
-	if (isDistributedRelation)
 	{
 		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-						errmsg("renaming distributed tables or their objects is "
+						errmsg("renaming distributed tables is currently unsupported")));
+	}
+	else if (renameStmt->renameType == OBJECT_TABCONSTRAINT)
+	{
+		ereport(ERROR, (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						errmsg("renaming constraints belonging to distributed tables is "
 							   "currently unsupported")));
 	}
 }
@@ -2099,11 +2135,12 @@ CreateLocalTable(RangeVar *relation, char *nodeName, int32 nodePort)
 
 
 /*
- * IsAlterTableRenameStmt returns true if the passed in RenameStmt operates on a
+ * IsAlterTableRenameStmt returns whether the passed-in RenameStmt is one of
- * distributed table or its objects. This includes:
+ * the following forms:
- * ALTER TABLE RENAME
+ *
- * ALTER TABLE RENAME COLUMN
+ *   - ALTER TABLE RENAME
- * ALTER TABLE RENAME CONSTRAINT
+ *   - ALTER TABLE RENAME COLUMN
+ *   - ALTER TABLE RENAME CONSTRAINT
  */
 static bool
 IsAlterTableRenameStmt(RenameStmt *renameStmt)

src/test/regress/expected/multi_name_lengths.out

@@ -125,9 +125,9 @@ DETAIL:  Citus cannot execute ADD CONSTRAINT command other than ADD CONSTRAINT F
 \c - - - :master_port
 -- Placeholders for RENAME operations
 ALTER TABLE name_lengths RENAME TO name_len_12345678901234567890123456789012345678901234567890;
-ERROR:  renaming distributed tables or their objects is currently unsupported
+ERROR:  renaming distributed tables is currently unsupported
 ALTER TABLE name_lengths RENAME CONSTRAINT unique_12345678901234567890123456789012345678901234567890 TO unique2_12345678901234567890123456789012345678901234567890;
-ERROR:  renaming distributed tables or their objects is currently unsupported
+ERROR:  renaming constraints belonging to distributed tables is currently unsupported
 -- Verify that CREATE INDEX on already distributed table has proper shard names.
 CREATE INDEX tmp_idx_12345678901234567890123456789012345678901234567890 ON name_lengths(col2);
 NOTICE:  using one-phase commit for distributed DDL commands

src/test/regress/expected/multi_reference_table.out

@@ -1359,7 +1359,7 @@ HINT:  You can enable two-phase commit for extra safety with: SET citus.multi_sh
 \c - - - :master_port
 -- as we expect, renaming and setting WITH OIDS does not work for reference tables
 ALTER TABLE reference_table_ddl RENAME TO reference_table_ddl_test;
-ERROR:  renaming distributed tables or their objects is currently unsupported
+ERROR:  renaming distributed tables is currently unsupported
 ALTER TABLE reference_table_ddl SET WITH OIDS;
 ERROR:  alter table command is currently unsupported
 DETAIL:  Only ADD|DROP COLUMN, SET|DROP NOT NULL, SET|DROP DEFAULT, ADD|DROP CONSTRAINT FOREIGN KEY and TYPE subcommands are supported.

src/test/regress/input/multi_alter_table_statements.source

@@ -98,6 +98,10 @@ ALTER TABLE lineitem_alter DROP COLUMN int_column1;
 ALTER TABLE lineitem_alter DROP COLUMN float_column;
 ALTER TABLE lineitem_alter DROP COLUMN date_column;
 
+-- Verify that RENAME COLUMN works
+ALTER TABLE lineitem_alter RENAME COLUMN l_orderkey TO l_orderkey_renamed;
+SELECT SUM(l_orderkey_renamed) FROM lineitem_alter;
+
 -- Verify that IF EXISTS works as expected
 
 ALTER TABLE non_existent_table ADD COLUMN new_column INTEGER;
@@ -107,6 +111,11 @@ ALTER TABLE IF EXISTS lineitem_alter ALTER COLUMN int_column2 SET DATA TYPE INTE
 ALTER TABLE lineitem_alter DROP COLUMN non_existent_column;
 ALTER TABLE lineitem_alter DROP COLUMN IF EXISTS non_existent_column;
 ALTER TABLE lineitem_alter DROP COLUMN IF EXISTS int_column2;
+
+-- Verify with IF EXISTS for extant table
+ALTER TABLE IF EXISTS lineitem_alter RENAME COLUMN l_orderkey_renamed TO l_orderkey;
+SELECT SUM(l_orderkey) FROM lineitem_alter;
+
 \d lineitem_alter
 
 -- Verify that we can execute commands with multiple subcommands
@@ -139,10 +148,9 @@ ALTER TABLE lineitem_alter ADD COLUMN new_column non_existent_type;
 ALTER TABLE lineitem_alter ALTER COLUMN null_column SET NOT NULL;
 ALTER TABLE lineitem_alter ALTER COLUMN l_partkey SET DEFAULT 'a';
 
--- Verify that we error out on statements involving RENAME
+-- Verify that we error out on non-column RENAME statements
 
 ALTER TABLE lineitem_alter RENAME TO lineitem_renamed;
-ALTER TABLE lineitem_alter RENAME COLUMN l_orderkey TO l_orderkey_renamed;
 ALTER TABLE lineitem_alter RENAME CONSTRAINT constraint_a TO constraint_b;
 
 -- Verify that IF EXISTS works as expected with RENAME statements
@@ -150,7 +158,6 @@ ALTER TABLE lineitem_alter RENAME CONSTRAINT constraint_a TO constraint_b;
 ALTER TABLE non_existent_table RENAME TO non_existent_table_renamed;
 ALTER TABLE IF EXISTS non_existent_table RENAME TO non_existent_table_renamed;
 ALTER TABLE IF EXISTS non_existent_table RENAME COLUMN column1 TO column2;
-ALTER TABLE IF EXISTS lineitem_alter RENAME l_orderkey TO l_orderkey_renamed;
 
 -- Verify that none of the failed alter table commands took effect on the master
 -- node

src/test/regress/output/multi_alter_table_statements.source

@@ -253,6 +253,14 @@ SELECT int_column2, pg_typeof(int_column2), count(*) from lineitem_alter GROUP B
 ALTER TABLE lineitem_alter DROP COLUMN int_column1;
 ALTER TABLE lineitem_alter DROP COLUMN float_column;
 ALTER TABLE lineitem_alter DROP COLUMN date_column;
+-- Verify that RENAME COLUMN works
+ALTER TABLE lineitem_alter RENAME COLUMN l_orderkey TO l_orderkey_renamed;
+SELECT SUM(l_orderkey_renamed) FROM lineitem_alter;
+   sum    
+----------
+ 53620791
+(1 row)
+
 -- Verify that IF EXISTS works as expected
 ALTER TABLE non_existent_table ADD COLUMN new_column INTEGER;
 ERROR:  relation "non_existent_table" does not exist
@@ -264,6 +272,14 @@ ERROR:  column "non_existent_column" of relation "lineitem_alter" does not exist
 ALTER TABLE lineitem_alter DROP COLUMN IF EXISTS non_existent_column;
 NOTICE:  column "non_existent_column" of relation "lineitem_alter" does not exist, skipping
 ALTER TABLE lineitem_alter DROP COLUMN IF EXISTS int_column2;
+-- Verify with IF EXISTS for extant table
+ALTER TABLE IF EXISTS lineitem_alter RENAME COLUMN l_orderkey_renamed TO l_orderkey;
+SELECT SUM(l_orderkey) FROM lineitem_alter;
+   sum    
+----------
+ 53620791
+(1 row)
+
 \d lineitem_alter
             Table "public.lineitem_alter"
      Column      |         Type          | Modifiers 
@@ -365,13 +381,11 @@ ERROR:  column "null_column" contains null values
 CONTEXT:  while executing command on localhost:57638
 ALTER TABLE lineitem_alter ALTER COLUMN l_partkey SET DEFAULT 'a';
 ERROR:  invalid input syntax for integer: "a"
--- Verify that we error out on statements involving RENAME
+-- Verify that we error out on non-column RENAME statements
 ALTER TABLE lineitem_alter RENAME TO lineitem_renamed;
-ERROR:  renaming distributed tables or their objects is currently unsupported
+ERROR:  renaming distributed tables is currently unsupported
-ALTER TABLE lineitem_alter RENAME COLUMN l_orderkey TO l_orderkey_renamed;
-ERROR:  renaming distributed tables or their objects is currently unsupported
 ALTER TABLE lineitem_alter RENAME CONSTRAINT constraint_a TO constraint_b;
-ERROR:  renaming distributed tables or their objects is currently unsupported
+ERROR:  renaming constraints belonging to distributed tables is currently unsupported
 -- Verify that IF EXISTS works as expected with RENAME statements
 ALTER TABLE non_existent_table RENAME TO non_existent_table_renamed;
 ERROR:  relation "non_existent_table" does not exist
@@ -379,8 +393,6 @@ ALTER TABLE IF EXISTS non_existent_table RENAME TO non_existent_table_renamed;
 NOTICE:  relation "non_existent_table" does not exist, skipping
 ALTER TABLE IF EXISTS non_existent_table RENAME COLUMN column1 TO column2;
 NOTICE:  relation "non_existent_table" does not exist, skipping
-ALTER TABLE IF EXISTS lineitem_alter RENAME l_orderkey TO l_orderkey_renamed;
-ERROR:  renaming distributed tables or their objects is currently unsupported
 -- Verify that none of the failed alter table commands took effect on the master
 -- node
 \d lineitem_alter