Most of the DBCC commands return their results as textual output, even if you have SSMS configured to return result sets to a grid. This makes examining the output a manual process that is prone to errors. It sure would be nice if there was a way to return the output to a grid.

If we were to examine Books Online (BOL) for DBCC in 2000 (http://technet.microsoft.com/en-us/library/aa258281%28v=sql.80%29.aspx) and 2005 (http://msdn.microsoft.com/en-us/library/ms188796%28v=sql.90%29.aspx), we would notice a section titled “Using DBCC Result Set Output”, with the phrase: “Many DBCC commands can produce output in tabular form by using the WITH TABLERESULTS option. This information can be loaded into a table for additional use.” This section has been removed from more recent versions, most likely because the results returned are not documented for the individual DBCC commands and are thus subject to change without notice.

Okay, let’s try this out. At the above BOL links, there are two DBCC commands that are documented to use the TABLERESULTS option: OPENTRAN and SHOWCONTIG. Testing all of the other DBCC commands shows that this option can also be used on the CHECKALLOC, CHECKDB, CHECKFILEGROUP and CHECKTABLE commands. I’m going to continue this post with using DBCC CHECKDB. If you check BOL, it does not mention the TABLERESULTS option. Let’s first see the results we get without the TABLERESULTS option by running:

For the consistency check that is performed on the master database, I end up with over 300 lines of output. The key lines in the output are:

And the final two lines:

(Notice that when we run CHECKDB against the master database, the hidden database mssqlsystemresource is also checked.)

If we were to modify the above statement to use the TABLERESULTS option:

we would actually get two result sets – one for the master database, and one for the hidden mssqlsystemresource database. Notice that the “DBCC execution completed…” line is not in either of the result sets – it is still displayed on the Messages tab.

Now, most people usually modify this command to suppress informational messages and to show all error messages (it defaults to “only” the first 200 error messages per object), so the command that is normally used would be:

And, hopefully, this only returns the message “Command completed successfully”. Let’s modify this command to use the TABLERESULTS option:

If there is no corruption in the database, it still returns only the message “Command completed successfully”. However, if there is corruption, you will get a result set back. So, I’m now going to run this against a database (Lab) where I have engineered some corruption. First off, let’s run CHECKDB without the TABLERESULTS option to check the initial output:

Here we can see that we indeed have corruption. Quickly now… is any of this corruption in a non-clustered index?

Running this statement with the TABLERESULTS option, we get a grid of the results:

DBCCTABLE1

(This screen shot is only showing some of the columns. Note that the message of the previous output for the minimum repair level is still on the Messages tab.)

As you can see, this already makes examining your errors somewhat easier. For instance, you can easily scroll through this output to see if the corruption is in non-clustered indexes (IndexId > 1), where the corruption could easily be fixed by scripting out the index definition, dropping and then re-creating the non-clustered index. Suppose you had over 100 errors… you can see how much faster this would be.

If you recall, the BOL description says that this data can be loaded into a table for further processing. Furthermore, this post is about persisting DBCC output data, which implies storing it into a table. So, let’s make a table, put these results into the table, and then run a query against it. First off, let’s make a local temporary table to hold the results (you could put this into a permanent table if you so desire):

Since the output from using TABLERESULTS isn’t documented, I’ve had to make some assumptions about the data types for these columns. To actually insert the output, we need to use the INSERT INTO … EXECUTE statement:

Now that we have the data stored in a temporary table, let’s run a query against the table to return some aggregated data.

— Get the objects, # of errors, and repair level

With which I get the following results:

DBCCTABLE2

So, there we go. Easy-peasy. By utilizing the TABLERESULTS option, the output of the DBCC CHECKDB command has been persisted into a table, and we are now able to run our own queries against that data. In the event that there is corruption in multiple indexes in a table, this query could easily be extended to get the number of errors in each index.

This post is re-published from my original post on SQL Solutions Group.