Io-Latency

Correlating IO Wait with Queries

Have you ever looked at sys.dm_os_virtual_file_stats and saw horrible latency for your database files? Generally speaking, you want to see latency below 20 ms on your database files.  much above that and there are some problems somewhere that need some tuning.

But, how do you know what queries are causing your issue? What’s causing those IO waits?

How to Find Queries Associated with Pending IO Requests

I responded to a question on SQLServerCentral.com about performance that is related to these types of scenarios. The poster wanted to know if there was a way to correlate pending io requests with the queries that were experiencing the waits using the DMV sys.dm_io_pending_requests.

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3 Reasons Not to Install Databases On the C Drive

We’re probably all familiar with the fact that SQL Server by default will install not only the program binaries but all your databases on the C drive as well.  Accidental DBA’s, i.e. System Administrators and Developers who inherited the maintenance of a database, may not be aware of how bad it can be if someone simply clicked the “Next” button all the way through the SQL Server install.  There are surely many reasons not to accept this default during the install, but I will start with three.

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