BUG: Unhandled Exception in SQL Server Using Keyset Cursors

ID: Q166233

The information in this article applies to:

Microsoft SQL Server version 6.5

BUG #: 16560 (SQLBUG_65)

SYMPTOMS

SQL Server seems to stop responding and becomes unresponsive when running cursor queries that require keyset cursors. The error log indicates an access violation (AV) and the following error:

closetable: table already closed for sdes '%*.d'

There is no message in the error log about SQL Server being shut down. The client receives the following error:

Error 10037 Unexpected EOF from SQL Server. Connection broken.

CAUSE

SQL Server 6.5 introduced the asynchronous generation of keysets for keyset cursors, using "subprocess." The optimizer decides the number of records in the result set based on the statistics information, and if this number is within the cursor threshold, the keyset values are generated synchronously. When this number exceeds the "cursor threshold" setting, it uses asynchronous generation of keysets by forking a "subprocess" to populate the keyset cursor. When the subprocess completes, it closes itself and while doing so, it generates an access violation that is not completely handled.

WORKAROUND

To work around this problem, either set the cursor threshold configuration parameter to a higher value, or set it to the default setting of -1 (all cursors will be generated synchronously). Also, running UPDATE STATISTICS to have latest distribution information may help the optimizer determine the result set more accurately.

STATUS

Microsoft has confirmed this to be a problem in SQL Server version 6.5.

Additional query words: errorlog sync synch async asynch hang hangs hung GPF terminate die freeze lock

Keywords : SSrvGPF SSrvRep kbbug6.50
Version : winnt:6.5
Platform : winnt
Issue type : kbbug