diff --git a/doc/src/sgml/ref/declare.sgml b/doc/src/sgml/ref/declare.sgml
index f823cf77bbe..269d2c101c4 100644
--- a/doc/src/sgml/ref/declare.sgml
+++ b/doc/src/sgml/ref/declare.sgml
@@ -1,5 +1,5 @@
@@ -172,7 +172,7 @@ DECLARE name [ BINARY ] [ INSENSITI
transaction. Thus, DECLARE without WITH
HOLD is useless outside a transaction block: the cursor would
survive only to the completion of the statement. Therefore
- PostgreSQL reports an error if this
+ PostgreSQL reports an error if such a
command is used outside a transaction block.
Use
,
@@ -230,6 +230,11 @@ DECLARE name [ BINARY ] [ INSENSITI
will have no effect if the row was changed meanwhile.
+
+ SCROLL may not be specified when the query
+ includes FOR UPDATE or FOR SHARE.
+
+
The SQL standard only makes provisions for cursors in embedded
SQL. The PostgreSQL
@@ -265,10 +270,11 @@ DECLARE liahona CURSOR FOR SELECT * FROM films;
Compatibility
- The SQL standard specifies that by default, cursors are sensitive to
- concurrent updates of the underlying data. In
+ The SQL standard says that it is implementation-dependent whether cursors
+ are sensitive to concurrent updates of the underlying data by default. In
PostgreSQL, cursors are insensitive by default,
- and can be made sensitive by specifying FOR UPDATE.
+ and can be made sensitive by specifying FOR UPDATE. Other
+ products may work differently.
diff --git a/src/backend/commands/portalcmds.c b/src/backend/commands/portalcmds.c
index 939452650d0..e8f21d4f083 100644
--- a/src/backend/commands/portalcmds.c
+++ b/src/backend/commands/portalcmds.c
@@ -14,7 +14,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.65 2007/04/27 22:05:47 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/commands/portalcmds.c,v 1.66 2007/10/24 23:27:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -102,12 +102,13 @@ PerformCursorOpen(PlannedStmt *stmt, ParamListInfo params,
*
* If the user didn't specify a SCROLL type, allow or disallow scrolling
* based on whether it would require any additional runtime overhead to do
- * so.
+ * so. Also, we disallow scrolling for FOR UPDATE cursors.
*/
portal->cursorOptions = cstmt->options;
if (!(portal->cursorOptions & (CURSOR_OPT_SCROLL | CURSOR_OPT_NO_SCROLL)))
{
- if (ExecSupportsBackwardScan(stmt->planTree))
+ if (stmt->rowMarks == NIL &&
+ ExecSupportsBackwardScan(stmt->planTree))
portal->cursorOptions |= CURSOR_OPT_SCROLL;
else
portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;
diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 875e4da2914..6d59401d0fb 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.181 2007/09/20 17:56:31 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/spi.c,v 1.182 2007/10/24 23:27:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -975,12 +975,29 @@ SPI_cursor_open(const char *name, SPIPlanPtr plan,
{
if (list_length(stmt_list) == 1 &&
IsA((Node *) linitial(stmt_list), PlannedStmt) &&
+ ((PlannedStmt *) linitial(stmt_list))->rowMarks == NIL &&
ExecSupportsBackwardScan(((PlannedStmt *) linitial(stmt_list))->planTree))
portal->cursorOptions |= CURSOR_OPT_SCROLL;
else
portal->cursorOptions |= CURSOR_OPT_NO_SCROLL;
}
+ /*
+ * Disallow SCROLL with SELECT FOR UPDATE. This is not redundant with
+ * the check in transformDeclareCursorStmt because the cursor options
+ * might not have come through there.
+ */
+ if (portal->cursorOptions & CURSOR_OPT_SCROLL)
+ {
+ if (list_length(stmt_list) == 1 &&
+ IsA((Node *) linitial(stmt_list), PlannedStmt) &&
+ ((PlannedStmt *) linitial(stmt_list))->rowMarks != NIL)
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("DECLARE CURSOR SCROLL ... FOR UPDATE/SHARE is not supported"),
+ errdetail("Scrollable cursors must be READ ONLY.")));
+ }
+
/*
* If told to be read-only, we'd better check for read-only queries.
* This can't be done earlier because we need to look at the finished,
diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index 3135d852467..567130b18db 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -17,7 +17,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.367 2007/06/23 22:12:51 tgl Exp $
+ * $PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.368 2007/10/24 23:27:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1623,6 +1623,20 @@ transformDeclareCursorStmt(ParseState *pstate, DeclareCursorStmt *stmt)
errmsg("DECLARE CURSOR WITH HOLD ... FOR UPDATE/SHARE is not supported"),
errdetail("Holdable cursors must be READ ONLY.")));
+ /* FOR UPDATE and SCROLL are not compatible */
+ if (result->rowMarks != NIL && (stmt->options & CURSOR_OPT_SCROLL))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("DECLARE CURSOR SCROLL ... FOR UPDATE/SHARE is not supported"),
+ errdetail("Scrollable cursors must be READ ONLY.")));
+
+ /* FOR UPDATE and INSENSITIVE are not compatible */
+ if (result->rowMarks != NIL && (stmt->options & CURSOR_OPT_INSENSITIVE))
+ ereport(ERROR,
+ (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+ errmsg("DECLARE CURSOR INSENSITIVE ... FOR UPDATE/SHARE is not supported"),
+ errdetail("Insensitive cursors must be READ ONLY.")));
+
/* We won't need the raw querytree any more */
stmt->query = NULL;
diff --git a/src/include/nodes/parsenodes.h b/src/include/nodes/parsenodes.h
index 412fadac54e..e1a6198e012 100644
--- a/src/include/nodes/parsenodes.h
+++ b/src/include/nodes/parsenodes.h
@@ -7,7 +7,7 @@
* Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
- * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.353 2007/09/03 18:46:30 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/parsenodes.h,v 1.354 2007/10/24 23:27:08 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -1479,7 +1479,7 @@ typedef struct CommentStmt
#define CURSOR_OPT_BINARY 0x0001 /* BINARY */
#define CURSOR_OPT_SCROLL 0x0002 /* SCROLL explicitly given */
#define CURSOR_OPT_NO_SCROLL 0x0004 /* NO SCROLL explicitly given */
-#define CURSOR_OPT_INSENSITIVE 0x0008 /* INSENSITIVE (unimplemented) */
+#define CURSOR_OPT_INSENSITIVE 0x0008 /* INSENSITIVE */
#define CURSOR_OPT_HOLD 0x0010 /* WITH HOLD */
#define CURSOR_OPT_FAST_PLAN 0x0020 /* prefer fast-start plan */
diff --git a/src/test/regress/expected/portals.out b/src/test/regress/expected/portals.out
index b6673073cdf..527550eabde 100644
--- a/src/test/regress/expected/portals.out
+++ b/src/test/regress/expected/portals.out
@@ -1073,40 +1073,31 @@ SELECT * FROM uctest;
23 | three
(2 rows)
--- sensitive cursor should show effects of updates or deletes
--- XXX current behavior is WRONG
-FETCH RELATIVE 0 FROM c1;
+DELETE FROM uctest WHERE CURRENT OF c1;
+SELECT * FROM uctest;
f1 | f2
----+-----
8 | one
(1 row)
-DELETE FROM uctest WHERE CURRENT OF c1;
-SELECT * FROM uctest;
- f1 | f2
-----+-------
- 23 | three
-(1 row)
-
DELETE FROM uctest WHERE CURRENT OF c1; -- no-op
SELECT * FROM uctest;
- f1 | f2
-----+-------
- 23 | three
+ f1 | f2
+----+-----
+ 8 | one
(1 row)
UPDATE uctest SET f1 = f1 + 10 WHERE CURRENT OF c1; -- no-op
SELECT * FROM uctest;
- f1 | f2
-----+-------
- 23 | three
+ f1 | f2
+----+-----
+ 8 | one
(1 row)
+--- sensitive cursors can't currently scroll back, so this is an error:
FETCH RELATIVE 0 FROM c1;
- f1 | f2
-----+----
-(0 rows)
-
+ERROR: cursor can only scan forward
+HINT: Declare it with SCROLL option to enable backward scan.
ROLLBACK;
SELECT * FROM uctest;
f1 | f2
diff --git a/src/test/regress/sql/portals.sql b/src/test/regress/sql/portals.sql
index bdf5956d69c..8275ed78c84 100644
--- a/src/test/regress/sql/portals.sql
+++ b/src/test/regress/sql/portals.sql
@@ -376,15 +376,13 @@ UPDATE uctest SET f1 = f1 + 10 WHERE CURRENT OF c1;
SELECT * FROM uctest;
UPDATE uctest SET f1 = f1 + 10 WHERE CURRENT OF c1;
SELECT * FROM uctest;
--- sensitive cursor should show effects of updates or deletes
--- XXX current behavior is WRONG
-FETCH RELATIVE 0 FROM c1;
DELETE FROM uctest WHERE CURRENT OF c1;
SELECT * FROM uctest;
DELETE FROM uctest WHERE CURRENT OF c1; -- no-op
SELECT * FROM uctest;
UPDATE uctest SET f1 = f1 + 10 WHERE CURRENT OF c1; -- no-op
SELECT * FROM uctest;
+--- sensitive cursors can't currently scroll back, so this is an error:
FETCH RELATIVE 0 FROM c1;
ROLLBACK;
SELECT * FROM uctest;