database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-06-14 18:42:34 +03:00
Code Activity

Disallow scrolling of FOR UPDATE/FOR SHARE cursors, so as to avoid problems

Browse Source 
in corner cases such as re-fetching a just-deleted row.  We may be able to
relax this someday, but let's find out how many people really care before
we invest a lot of work in it.  Per report from Heikki and subsequent
discussion.

While in the neighborhood, make the combination of INSENSITIVE and FOR UPDATE
throw an error, since they are semantically incompatible.  (Up to now we've
accepted but just ignored the INSENSITIVE option of DECLARE CURSOR.)
This commit is contained in:
Tom Lane
2007-10-24 23:27:08 +00:00
parent 8a35b07e18
commit 048efc25e4
7 changed files with 62 additions and 35 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/commands/portalcmds.c
View File

@ -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;