1 files changed, 23 insertions, 13 deletions

diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 56cf592e0ce..d8678e5b3fd 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -74,7 +74,7 @@ typedef uint32 AclMode;			/* a bitmask of privilege bits */
 #define ACL_CONNECT		(1<<11) /* for databases */
 #define N_ACL_RIGHTS	12		/* 1 plus the last 1<<x */
 #define ACL_NO_RIGHTS	0
-/* Currently, SELECT ... FOR UPDATE/FOR SHARE requires UPDATE privileges */
+/* Currently, SELECT ... FOR [KEY] UPDATE/SHARE requires UPDATE privileges */
 #define ACL_SELECT_FOR_UPDATE	ACL_UPDATE
 
 
@@ -119,7 +119,7 @@ typedef struct Query
 	bool		hasDistinctOn;	/* distinctClause is from DISTINCT ON */
 	bool		hasRecursive;	/* WITH RECURSIVE was specified */
 	bool		hasModifyingCTE;	/* has INSERT/UPDATE/DELETE in WITH */
-	bool		hasForUpdate;	/* FOR UPDATE or FOR SHARE was specified */
+	bool		hasForUpdate;	/* FOR [KEY] UPDATE/SHARE was specified */
 
 	List	   *cteList;		/* WITH list (of CommonTableExpr's) */
 
@@ -572,18 +572,28 @@ typedef struct DefElem
 } DefElem;
 
 /*
- * LockingClause - raw representation of FOR UPDATE/SHARE options
+ * LockingClause - raw representation of FOR [NO KEY] UPDATE/[KEY] SHARE
+ * 		options
  *
  * Note: lockedRels == NIL means "all relations in query".	Otherwise it
  * is a list of RangeVar nodes.  (We use RangeVar mainly because it carries
  * a location field --- currently, parse analysis insists on unqualified
  * names in LockingClause.)
  */
+typedef enum LockClauseStrength
+{
+	/* order is important -- see applyLockingClause */
+	LCS_FORKEYSHARE,
+	LCS_FORSHARE,
+	LCS_FORNOKEYUPDATE,
+	LCS_FORUPDATE
+} LockClauseStrength;
+
 typedef struct LockingClause
 {
 	NodeTag		type;
-	List	   *lockedRels;		/* FOR UPDATE or FOR SHARE relations */
-	bool		forUpdate;		/* true = FOR UPDATE, false = FOR SHARE */
+	List	   *lockedRels;		/* FOR [KEY] UPDATE/SHARE relations */
+	LockClauseStrength strength;
 	bool		noWait;			/* NOWAIT option */
 } LockingClause;
 
@@ -865,21 +875,21 @@ typedef struct WindowClause
 
 /*
  * RowMarkClause -
- *	   parser output representation of FOR UPDATE/SHARE clauses
+ *	   parser output representation of FOR [KEY] UPDATE/SHARE clauses
  *
  * Query.rowMarks contains a separate RowMarkClause node for each relation
- * identified as a FOR UPDATE/SHARE target.  If FOR UPDATE/SHARE is applied
- * to a subquery, we generate RowMarkClauses for all normal and subquery rels
- * in the subquery, but they are marked pushedDown = true to distinguish them
- * from clauses that were explicitly written at this query level.  Also,
- * Query.hasForUpdate tells whether there were explicit FOR UPDATE/SHARE
- * clauses in the current query level.
+ * identified as a FOR [KEY] UPDATE/SHARE target.  If one of these clauses
+ * is applied to a subquery, we generate RowMarkClauses for all normal and
+ * subquery rels in the subquery, but they are marked pushedDown = true to
+ * distinguish them from clauses that were explicitly written at this query
+ * level.  Also, Query.hasForUpdate tells whether there were explicit FOR
+ * UPDATE/SHARE/KEY SHARE clauses in the current query level.
  */
 typedef struct RowMarkClause
 {
 	NodeTag		type;
 	Index		rti;			/* range table index of target relation */
-	bool		forUpdate;		/* true = FOR UPDATE, false = FOR SHARE */
+	LockClauseStrength strength;
 	bool		noWait;			/* NOWAIT option */
 	bool		pushedDown;		/* pushed down from higher query level? */
 } RowMarkClause;