You create a table that contains indexes in Microsoft SQL Server 2000 or in Microsoft SQL Server 2005. When you run the DBCC CHECKDB statement against the database that contains this table, you do not receive an error message. However, when you run a query that references this table, an access violation occurs.

This problem occurs for many reasons. One reason is that the statistics group of a table index is corrupted. However, the DBCC CHECKDB statement does not detect a corrupted statistics group. Therefore, when the query optimizer loads a corrupted statistic group to determine the most efficient execution plan, an access violation occurs. Depending on the cause of the corrupted statistics group, the actual access violation may vary.

The following issues are some common causes of a corrupted statistics group:

• The columns on which the database engine builds the statistics contain impure data.
• Hardware problems exist.

To work around this problem, follow these steps:

1. Determine whether the access violation is caused by a corrupted statistics group. To do this, run the DBCC SHOW_STATISTICS statement against all indexes on the tables that are referenced in the query.
2. If an access violation occurs when you run one of these DBCC SHOW_STATISTICS statements, repair the statistics that cause the access violation. To repair the statistics, run the UPDATE STATISTICS statement against the corrupted statistics group.
   
   If no access violation occurs when you run these DBCC SHOW_STATISTICS statements, the access violation that you encountered when you ran the query may be unrelated to corrupted statistics. For more information, see the "More Information" section.

Microsoft has confirmed that this is a bug in the Microsoft products that are listed in the "Applies to" section.

More information about the DBCC SHOW_STATISTICS statement

The DBCC SHOW_STATISTICS statement raises an access violation only when the statistics group contains physical corruption.

The DBCC SHOW_STATISTICS statement does not raise an access violation if the statistics group contains logical corruption. However, if the query optimizer uses a statistics group that contains logical corruption, an access violation still occurs.

For more information about the DBCC SHOW_STATISTICS statement, visit the following Microsoft Developer Network (MSDN) Web site: For more information about the UPDATE STATISTICS statement, visit the following MSDN Web site: