Article ID: 158288
Article Last Modified on 10/3/2003
APPLIES TO
- Microsoft SQL Server 6.5 Standard Edition
This article was previously published under Q158288
BUG #: 16082 (6.50)
SYMPTOMS
Using Dynamic Cursor within a user-defined transaction can cause hundreds
of 1203 errors in the SQL Server errorlog and Windows NT Event Viewer. The
SQL Server shuts down afterwards, with the following error message:
Error: 1203, Severity: 20, State: 2
Caller of lock manager is incorrectly trying to unlock an unlocked object.
spid=%d locktype=%d dbid=%d lockid=%Id
CAUSE
Dynamic Cursor scans through all data pages in the table, starting from the
first page. When it accumulates enough SH_PAGE locks on the table, lock
promotion occurs, which frees all SH_PAGE locks, and it acquires a table
lock instead. Cursor fetch has no knowledge of the lock promotion, so it
finishes its scan and tries to free SH_PAGE lock. However, SH_PAGE lock is
no longer there, which causes the problem.
WORKAROUND
To work around this problem, do one of the following:
- Change the cursor definition to use either SCROLL or INSENSITIVE.
-or-
- Increase "LE Threshold Maximum" setting in sp_configure.
-or-
- Do not use transaction around Dynamic Cursor.
STATUS
Microsoft has confirmed this to be a problem in Microsoft SQL Server
version 6.5. This problem has been corrected in U.S. Service Pack 2 for
Microsoft SQL Server version 6.5. For more information, contact your
primary support provider.
MORE INFORMATION
Trace flag 1200 can be used to monitor the lock promotion in this case.
Additional query words: unhandled exception
Keywords: kbbug kbfix kbnetwork KB158288