Product Reviews

Log Explorer unlocks your SQL Server Transaction Logs

A must-have tool for the professional DBA.

Lumigent calls this application a "transaction analysis and data recovery solution for Microsoft SQL Server." I call it an essential tool for the SQL Server 7.0 or SQL Server 2000 DBA whose users make mistakes. As far as I know, that would be *every* DBA out there.

SQL Server, of course, keeps track of everything that affects data in a transaction log, which is periodically rolled over into backup files (at least, if you're being a conscientious DBA it is). But SQL Server itself provides you with no way to see what's in the transaction log. If something goes wrong with your database, you can restore from a backup -- but there's no way to see in advance what that restore will do to the data. Enter Log Explorer.

The process is simplicity itself. You choose a server, a database, and a transaction log (either live or backed up). Then you can view every transaction in the log -- what happened, when it happened, who the user was, and exactly what data changed, was added, or was deleted. But better yet, you can do thing with these transactions. User accidentally deleted a row? No problem; right-click, select Undo Transaction, and Log Explorer will generate a SQL Script for you that re-inserts the deleted data. You can run the script directly from Log Explorer or from other tools such as Query Analyzer. You can also create "redo transaction" scripts -- useful for transferring changes from one server to another. A script can reverse or recreate a single transaction, everything in a log, or a filtered subset of the logged transactions (and the filtering tools are pretty good, too).

Other nice touches include the ability to recover entire deleted tables and a real-time transaction monitor mode. Another handy section lets you analyze the user load on your server and see which tables had the heaviest activity. All in all, I can't imagine trying to run a busy SQL Server installation without having this tool available. When I think about all the time that Log Explorer *could* have saved me in the past, I realize it would have paid for itself multiple times over.

About the Author

Mike Gunderloy, MCSE, MCSD, MCDBA, is a former MCP columnist and the author of numerous development books.


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