Add a RESTART (without parameter) option to ALTER SEQUENCE, allowing a

sequence to be reset to its original starting value.  This requires adding the
original start value to the set of parameters (columns) of a sequence object,
which is a user-visible change with potential compatibility implications;
it also forces initdb.

Also add hopefully-SQL-compatible RESTART/CONTINUE IDENTITY options to
TRUNCATE TABLE.  RESTART IDENTITY executes ALTER SEQUENCE RESTART for all
sequences "owned by" any of the truncated relations.  CONTINUE IDENTITY is
a no-op option.

Zoltan Boszormenyi

2 files changed, 25 insertions, 10 deletions

diff --git a/src/backend/parser/gram.y b/src/backend/parser/gram.y
index 56a56627e7f..591920d6f68 100644
--- a/src/backend/parser/gram.y
+++ b/src/backend/parser/gram.y
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.614 2008/04/29 20:44:49 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/gram.y,v 2.615 2008/05/16 23:36:05 tgl Exp $
  *
  * HISTORY
  *	  AUTHOR			DATE			MAJOR EVENT
@@ -206,7 +206,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 %type <str>		OptSchemaName
 %type <list>	OptSchemaEltList
 
-%type <boolean> TriggerActionTime TriggerForSpec opt_trusted
+%type <boolean> TriggerActionTime TriggerForSpec opt_trusted opt_restart_seqs
 %type <str>		opt_lancompiler
 
 %type <str>		TriggerEvents
@@ -381,7 +381,7 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 	CHARACTER CHARACTERISTICS CHECK CHECKPOINT CLASS CLOSE
 	CLUSTER COALESCE COLLATE COLUMN COMMENT COMMIT
 	COMMITTED CONCURRENTLY CONFIGURATION CONNECTION CONSTRAINT CONSTRAINTS
-	CONTENT_P CONVERSION_P COPY COST CREATE CREATEDB
+	CONTENT_P CONTINUE_P CONVERSION_P COPY COST CREATE CREATEDB
 	CREATEROLE CREATEUSER CROSS CSV CURRENT_P CURRENT_DATE CURRENT_ROLE
 	CURRENT_TIME CURRENT_TIMESTAMP CURRENT_USER CURSOR CYCLE
 
@@ -399,10 +399,10 @@ static Node *makeXmlExpr(XmlExprOp op, char *name, List *named_args, List *args)
 
 	HANDLER HAVING HEADER_P HOLD HOUR_P
 
-	IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IN_P INCLUDING INCREMENT
-	INDEX INDEXES INHERIT INHERITS INITIALLY INNER_P INOUT INPUT_P
-	INSENSITIVE INSERT INSTEAD INT_P INTEGER INTERSECT
-	INTERVAL INTO INVOKER IS ISNULL ISOLATION
+	IDENTITY_P IF_P ILIKE IMMEDIATE IMMUTABLE IMPLICIT_P IN_P
+	INCLUDING INCREMENT INDEX INDEXES INHERIT INHERITS INITIALLY
+	INNER_P INOUT INPUT_P INSENSITIVE INSERT INSTEAD INT_P INTEGER
+	INTERSECT INTERVAL INTO INVOKER IS ISNULL ISOLATION
 
 	JOIN
 
@@ -2489,6 +2489,10 @@ OptSeqElem: CACHE NumericOnly
 				{
 					$$ = makeDefElem("start", (Node *)$3);
 				}
+			| RESTART
+				{
+					$$ = makeDefElem("restart", NULL);
+				}
 			| RESTART opt_with NumericOnly
 				{
 					$$ = makeDefElem("restart", (Node *)$3);
@@ -3364,15 +3368,22 @@ attrs:		'.' attr_name
  *****************************************************************************/
 
 TruncateStmt:
-			TRUNCATE opt_table qualified_name_list opt_drop_behavior
+			TRUNCATE opt_table qualified_name_list opt_restart_seqs opt_drop_behavior
 				{
 					TruncateStmt *n = makeNode(TruncateStmt);
 					n->relations = $3;
-					n->behavior = $4;
+					n->restart_seqs = $4;
+					n->behavior = $5;
 					$$ = (Node *)n;
 				}
 		;
 
+opt_restart_seqs:
+			CONTINUE_P IDENTITY_P		{ $$ = false; }
+			| RESTART IDENTITY_P		{ $$ = true; }
+			| /* EMPTY */				{ $$ = false; }
+		;
+
 /*****************************************************************************
  *
  *	The COMMENT ON statement can take different forms based upon the type of
@@ -8964,6 +8975,7 @@ unreserved_keyword:
 			| CONNECTION
 			| CONSTRAINTS
 			| CONTENT_P
+			| CONTINUE_P
 			| CONVERSION_P
 			| COPY
 			| COST
@@ -9014,6 +9026,7 @@ unreserved_keyword:
 			| HEADER_P
 			| HOLD
 			| HOUR_P
+			| IDENTITY_P
 			| IF_P
 			| IMMEDIATE
 			| IMMUTABLE
diff --git a/src/backend/parser/keywords.c b/src/backend/parser/keywords.c
index b5312a487fd..46b306b98d1 100644
--- a/src/backend/parser/keywords.c
+++ b/src/backend/parser/keywords.c
@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.195 2008/03/27 03:57:33 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/parser/keywords.c,v 1.196 2008/05/16 23:36:05 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -101,6 +101,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"constraint", CONSTRAINT, RESERVED_KEYWORD},
 	{"constraints", CONSTRAINTS, UNRESERVED_KEYWORD},
 	{"content", CONTENT_P, UNRESERVED_KEYWORD},
+	{"continue", CONTINUE_P, UNRESERVED_KEYWORD},
 	{"conversion", CONVERSION_P, UNRESERVED_KEYWORD},
 	{"copy", COPY, UNRESERVED_KEYWORD},
 	{"cost", COST, UNRESERVED_KEYWORD},
@@ -181,6 +182,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"header", HEADER_P, UNRESERVED_KEYWORD},
 	{"hold", HOLD, UNRESERVED_KEYWORD},
 	{"hour", HOUR_P, UNRESERVED_KEYWORD},
+	{"identity", IDENTITY_P, UNRESERVED_KEYWORD},
 	{"if", IF_P, UNRESERVED_KEYWORD},
 	{"ilike", ILIKE, TYPE_FUNC_NAME_KEYWORD},
 	{"immediate", IMMEDIATE, UNRESERVED_KEYWORD},