SYMPTOMS

If you update a row in a table that contains text or image column(s), without updating the text/image column(s) for the row, NULL is sent across for the text/image column(s) during replication. This overwrites any existing text or image data at the subscriber even though the publisher has the correct data for the column(s). This happens only in a transaction- based publication, when either of the following conditions are true:

• You use custom stored procedures for replicating update operations.

  -or-

• You use horizontal partitioning using a replication filter and the update affects the column(s) used in the filter.

Text/image logging does not include data for the unmodified text/image columns; therefore, the data is passed as NULL.

WORKAROUND

If you have a text/image column in your table that is a part of a transaction-based publication using partitioning or custom stored procedures, ensure that all update operations update the text/image column.

Alternately, use Scheduled Table Refresh for tables containing text/image columns.

Another complex workaround is to ignore updates to the text/image column if it is NULL at the subscriber in the custom stored procedure. However, this will be a problem if the desired update to the text/image column is NULL. In this case, add a "status" column to the table and use this column to indicate that NULL is the desired value for the text/image column. All updates of the text/image column should update the "status" column.

STATUS

Microsoft has confirmed this to be a problem in Microsoft SQL Server version 6.5. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.