BUG: LogReader Generates an AV on DELETE/INSERT of Text Columns (192489)
The information in this article applies to:
This article was previously published under Q192489 SYMPTOMS
The LogReader task generates an access violation (AV) when you have a
single transaction that does a delete on a table with a text or image
column followed by one or more inserts into the same table. This happens
only when the DELETE/INSERT commands are inside a user-defined transaction
and the deleted record had a valid value for the text or image column and
the inserted record has a NULL value for the text or image column.
CAUSE
The LogReader tries to regenerate commands based on the transaction log
entries. In this case, it tries to regenerate an UPDATE statement that
would have the same effect as the DELETE/INSERT command and generates the
AV in the process of reading the text or image value.
WORKAROUND
Avoid using explicit transactions on tables with text or image datatypes,
when the deleted and inserted records would fit in the same page. The
LogReader generates DELETE and INSERT commands if the inserted record does
not fall in the same page as the deleted record. If you cannot avoid using
explicit transactions, consider adding a fill factor (or lowering an
existing one) on your clustered index so that the chances of the inserted
record falling in the same page are reduced. This will reduce occurrences
of this problem and may not avoid the problem completely.
You can also work around the problem by using an optional trace flag to
make the LogReader generate DELETE/INSERT pairs for all updates. For
additional information about the trace flag and command generation in
LogReader, please see the following article in the Microsoft Knowledge
Base:
160181
: INF: Trace Flag to Replicate UPDATE as DELETE/INSERT Pair
STATUS
Microsoft has confirmed this to be a problem in SQL Server version 6.5.
| Modification Type: | Minor | Last Reviewed: | 3/2/2005 |
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| Keywords: | kbBug kbpending KB192489 |
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