Aaron Bertrand (@AaronBertrand) discusses several aspects of DBCC CHECKDB and offers suggestions to minimize the impact this crucial operation can have.Continue Reading »
Numerous licensing changes were introduced in SQL Server 2012; the most significant was the move from socket-based licensing to core-based licensing for Enterprise Edition. One of the challenges that Microsoft faced with this change was providing a migration path for customers that previously used Server+CAL based licensing for Enterprise Edition prior to SQL Server 2012. Customers under Software Assurance can upgrade to SQL Server 2012 Enterprise Edition and still use Server+CAL licensing (also known as "grandfathering") but with a limitation to 20 logical processors, as documented in the SQL Server 2012 Licensing Guide.Continue Reading »
Primary and foreign keys are fundamental characteristics of relational databases, as originally noted in E.F. Codd’s paper, “A Relational Model of Data for Large Shared Data Banks”, published in 1970. The quote often repeated is, "The key, the whole key, and nothing but the key, so help me Codd."
In this post, Erin Stellato (@erinstellato) discusses the benefits of adding indexes on top of declared referential constraints.Continue Reading »
Here's a quick tip for you:
During some restore operations in SQL Server, the transaction log redo step might be taking an unusually long time. Depending somewhat on the version and edition of SQL Server you've installed, you may be able to increase performance by tinkering with the readahead performance for the redo operations. To do this, you should use the
MAXTRANSFERSIZE parameter of the
RESTORE statement. For example, if you set
MAXTRANSFERSIZE = 1048576, it'll use 1MB buffers.
The quality of an execution plan is highly dependent on the accuracy of the estimated number of rows output by each plan operator. If the estimated number of rows is significantly skewed from the actual number of rows, this can have a significant impact on the quality of a query's execution plan. Poor plan quality can be responsible for excessive I/O, inflated CPU, memory pressure, decreased throughput and reduced overall concurrency.Continue Reading »
As you have most certainly heard elsewhere, SQL Server 2012 finally offers a version of Extended Events that is a viable alternative to SQL Trace, in terms of both better performance and event parity. There are other enhancements such as a usable UI in Management Studio – previously your only hope for this was Jonathan Kehayias' Extended Events Manager.Continue Reading »
I have a few people to thank for a recent update to Plan Explorer. Brooke Philpott (@Macromullet) and Greg Gonzalez (blog | @SQLsensei), of course, for R & D and for digging into the code and sorting it out. But also to Paul White (blog | @SQL_kiwi) for being persistent in helping us validate the fixes.Continue Reading »