drop_database_force.v1.patch

diff --git a/src/backend/commands/dbcommands.c b/src/backend/commands/dbcommands.c
index 9a9b4cb..8b1878c 100644
--- a/src/backend/commands/dbcommands.c
+++ b/src/backend/commands/dbcommands.c
@@ -732,7 +732,7 @@ createdb_failure_callback(int code, Datum arg)
  * DROP DATABASE
  */
 void
-dropdb(const char *dbname, bool missing_ok)
+dropdb(const char *dbname, bool missing_ok, bool force)
 {
 	Oid			db_id;
 	bool		db_istemplate;
@@ -800,11 +800,16 @@ dropdb(const char *dbname, bool missing_ok)
 	 * As in CREATE DATABASE, check this after other error conditions.
 	 */
 	if (CountOtherDBBackends(db_id, &notherbackends, &npreparedxacts))
-		ereport(ERROR,
+	{
+		if (force)
+			ResolveRecoveryConflictWithDatabase(db_id);
+		else
+			ereport(ERROR,
 				(errcode(ERRCODE_OBJECT_IN_USE),
 				 errmsg("database \"%s\" is being accessed by other users",
 						dbname),
 				 errdetail_busy_db(notherbackends, npreparedxacts)));
+	}
 
 	/*
 	 * Remove the database's tuple from pg_database.
diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index fb9da83..ee595af 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -3074,6 +3074,7 @@ _copyDropdbStmt(DropdbStmt *from)
 
 	COPY_STRING_FIELD(dbname);
 	COPY_SCALAR_FIELD(missing_ok);
+	COPY_SCALAR_FIELD(force);
 
 	return newnode;
 }
diff --git a/src/backend/nodes/equalfuncs.c b/src/backend/nodes/equalfuncs.c
index 2ef1a33..60d4e8c 100644
--- a/src/backend/nodes/equalfuncs.c
+++ b/src/backend/nodes/equalfuncs.c
@@ -1523,6 +1523,7 @@ _equalDropdbStmt(DropdbStmt *a, DropdbStmt *b)
 {
 	COMPARE_STRING_FIELD(dbname);
 	COMPARE_SCALAR_FIELD(missing_ok);
+	COMPARE_SCALAR_FIELD(force);
 
 	return true;
 }
diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 660947c..ec67cf5 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -6973,18 +6973,20 @@ alterdb_opt_item:
  * This is implicitly CASCADE, no need for drop behavior
  *****************************************************************************/
 
-DropdbStmt: DROP DATABASE database_name
+DropdbStmt: DROP DATABASE database_name opt_force
 				{
 					DropdbStmt *n = makeNode(DropdbStmt);
 					n->dbname = $3;
 					n->missing_ok = FALSE;
+					n->force = $4;
 					$$ = (Node *)n;
 				}
-			| DROP DATABASE IF_P EXISTS database_name
+			| DROP DATABASE IF_P EXISTS database_name opt_force
 				{
 					DropdbStmt *n = makeNode(DropdbStmt);
 					n->dbname = $5;
 					n->missing_ok = TRUE;
+					n->force = $6;
 					$$ = (Node *)n;
 				}
 		;
diff --git a/src/backend/tcop/utility.c b/src/backend/tcop/utility.c
index 9500037..28dfbe2 100644
--- a/src/backend/tcop/utility.c
+++ b/src/backend/tcop/utility.c
@@ -995,7 +995,7 @@ standard_ProcessUtility(Node *parsetree,
 				DropdbStmt *stmt = (DropdbStmt *) parsetree;
 
 				PreventTransactionChain(isTopLevel, "DROP DATABASE");
-				dropdb(stmt->dbname, stmt->missing_ok);
+				dropdb(stmt->dbname, stmt->missing_ok, stmt->force);
 			}
 			break;
 
diff --git a/src/include/commands/dbcommands.h b/src/include/commands/dbcommands.h
index 8097547..eea939b 100644
--- a/src/include/commands/dbcommands.h
+++ b/src/include/commands/dbcommands.h
@@ -53,7 +53,7 @@ typedef struct xl_dbase_drop_rec
 } xl_dbase_drop_rec;
 
 extern void createdb(const CreatedbStmt *stmt);
-extern void dropdb(const char *dbname, bool missing_ok);
+extern void dropdb(const char *dbname, bool missing_ok, bool force);
 extern void RenameDatabase(const char *oldname, const char *newname);
 extern void AlterDatabase(AlterDatabaseStmt *stmt, bool isTopLevel);
 extern void AlterDatabaseSet(AlterDatabaseSetStmt *stmt);
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 3d2ae99..f104a1b 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -2293,6 +2293,7 @@ typedef struct DropdbStmt
 	NodeTag		type;
 	char	   *dbname;			/* database to drop */
 	bool		missing_ok;		/* skip error if db is missing? */
+	bool		force;			/* force off any users before drop? */
 } DropdbStmt;
 
 /* ----------------------