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Co-authored-by: Onur Tirtir <onurcantirtir@gmail.com>

src/backend/distributed/commands/database.c

@@ -275,7 +275,7 @@ PreprocessAlterDatabaseSetStmt(Node *node, const char *queryString,
  * postgres instance.
  *
  * In this stage, we can perform validations and prepare the commands that need to
- * be run on all workers to grant.
+ * be run on all workers to create the database.
  */
 List *
 PreprocessCreateDatabaseStmt(Node *node, const char *queryString,
@@ -298,7 +298,9 @@ PreprocessCreateDatabaseStmt(Node *node, const char *queryString,
 /*
  * PostprocessCreatedbStmt is executed after the statement is applied to the local
  * postgres instance. In this stage we can prepare the commands that need to be run on
- * all workers to create the database.
+ * all workers to create the database. Since the CREATE DATABASE statement gives error 
+ * in a transaction block, we need to use NontransactionalNodeDDLTaskList to send the
+ * CREATE DATABASE statement to the workers.
  *
  */
 List *

src/backend/distributed/deparser/citus_deparseutils.c

@@ -1,11 +1,15 @@
-/*
+/*-------------------------------------------------------------------------
+ *
  * citus_deparseutils.c
- * ---------------------
  *
- * This file contains common functions used for deparsing PostgreSQL statements
+ *   This file contains common functions used for deparsing PostgreSQL
- * to their equivalent SQL representation.
+ *   statements to their equivalent SQL representation.
  *
+ * Copyright (c) Citus Data, Inc.
+ *
+ *-------------------------------------------------------------------------
  */
+
 #include "pg_version_constants.h"
 
 #include "postgres.h"
@@ -31,9 +35,9 @@
  * @param optionFormatsLen The number of option formats in the opt_formats array.
  */
 void
-DefElemOptionToStatement(StringInfo buf, DefElem *option, const
+DefElemOptionToStatement(StringInfo buf, DefElem *option,
-						 DefElemOptionFormat *optionFormats, int
+						 const DefElemOptionFormat *optionFormats,
-						 optionFormatsLen)
+						 int optionFormatsLen)
 {
 	const char *name = option->defname;
 	int i;

src/backend/distributed/metadata/distobject.c

@@ -360,8 +360,10 @@ ExecuteCommandAsSuperuser(char *query, int paramCount, Oid *paramTypes,
 
 
 /*
- * Deletes all pg_dist_object records for distributed roles in `DROP ROLE` statement a
+ * UnmarkNodeWideObjectsDistributed deletes pg_dist_object records
- * and for all databases in `DROP DATABASE` statement
+ * for all distributed objects in given Drop stmt node.
+ *
+ * Today we only expect DropRoleStmt and DropdbStmt to get here.
  */
 void
 UnmarkNodeWideObjectsDistributed(Node *node)

src/backend/distributed/metadata/metadata_sync.c

@@ -3902,11 +3902,13 @@ Datum
 citus_internal_database_command(PG_FUNCTION_ARGS)
 {
 	CheckCitusVersion(ERROR);
+
 	if (!ShouldSkipMetadataChecks())
 	{
 		EnsureCitusInitiatedOperation();
 	}
-	PG_ENSURE_ARGNOTNULL(0, "database command");
+
+	PG_ENSURE_ARGNOTNULL(0, "command");
 
 	text *commandText = PG_GETARG_TEXT_P(0);
 	char *command = text_to_cstring(commandText);
@@ -3960,7 +3962,7 @@ citus_internal_database_command(PG_FUNCTION_ARGS)
 		ereport(ERROR, (errmsg("unsupported command type %d", nodeTag(parseTree))));
 	}
 
-	/* Rollbacks GUCs to the state before this session */
+	/* rollback GUCs to the state before this session */
 	AtEOXact_GUC(true, saveNestLevel);
 
 	PG_RETURN_VOID();

src/include/distributed/deparser.h

@@ -140,9 +140,9 @@ typedef enum OptionFormatType
 } OptionFormatType;
 
 
-extern void DefElemOptionToStatement(StringInfo buf, DefElem *option, const
+extern void DefElemOptionToStatement(StringInfo buf, DefElem *option,
-									 DefElemOptionFormat *opt_formats, int
+									 const DefElemOptionFormat *opt_formats,
-									 opt_formats_len);
+									 int opt_formats_len);
 
 
 /* forward declarations for deparse_statistics_stmts.c */