When I first started poking around in SQL Server 2012, I noticed an extended event session called “system_health” was created by default. It took me a few months before I really dug into the session details to see what it was capturing. But once I did, I was pretty amazed. The system_health session starts up by default and collects various performance points that can be used to help troubleshoot issues on the server. To look at the details of it, just right click on the event session and choose properties. This will open the Extended Events UI. Select the events...
Continue reading...Patrick Keisler
How Long is that SQL Command Going to Take?
Have you ever needed to restore a large database while someone is standing over your shoulder asking “How long is that going to take”? If that hasn’t happened to you yet, then it’s only a matter of time. Let’s throw out all the reasons why you need to do the restore and just discuss the technical part. Obviously the easiest way to know how long the restore will take is to use the “WITH STATS” option in the restore database command. But let’s say in the heat of the moment you forgot that little piece of the statement. Now what?...
Continue reading...My Experience Aboard SQL Cruise 2014
Where do I begin? First let me say, WOW what an experience! How it All Began When I first heard about SQL Cruise way back in 2012, I thought the idea of hosting training sessions aboard a cruise ship was a swell idea. However, talking my wife into going with me on the cruise or even letting me go on my own was next to impossible. Don’t get me wrong, my wife and I love cruising and we even took a cruise to our destination wedding in Bermuda. But no matter how I argued, my wife would not budge. We...
Continue reading...Collecting Historical IO File Statistics
In a previous post, Collecting Historical Wait Statistics, I discussed how you can easily collect historical wait stats by using the DMV sys.dm_os_wait_stats. Well today, I’d like to cover the same concept, but this time collect historical IO file stats from the DMV, sys.dm_io_virtual_files_stats. However, I wanted to improve on the code to make it even easier to implement. The data collection process is still implemented the same way. First, we’ll need to create a history table to store the data. The data is stored in time slices with the cumulative values as well as the difference (TimeDiff_ms, NumOfReadsDiff, NumOfWritesDiff,...
Continue reading...Collecting Historical Wait Statistics
As a DBA, I’m sure you’ve heard many times to always check the sys.dm_os_wait_stats DMV to help diagnose performance issues on your server. The DMV returns information about specific resources SQL Server had to wait for while processing queries. The counters in the DMV are cumulative since the last time SQL Server was started and the counters can only be reset by a service restart or by using a DBCC command. Since DMVs don’t persist their data beyond a service restart, we need to come up with a way to collect this data and be able to run trending reports...
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