You’ve got a performance problem and you know just the cool index trick that will fix it!
Until it goes utterly wrong.
Join me for this free session in the 24 hours of PASS to see multiple quick demos of index changes that seem like a great idea… until they either don’t work, or make things worse.
My session is on Wed, July 19, 9 am Pacific / 12 pm Eastern / 4pm UTC.
SQL Server has more than one way to pull pages in from disk for your queries. SQL Server can do a physical read of an 8KB page, or an extent of 8 of those 8KB pages.
I’ve got a whole bunch of free, live webcasts scheduled on SQL Server training! I’d love for you to join me for these sessions.
Batch mode was introduced as a way to help SQL Server process data from columnstore indexes faster. The whole idea with columnstore is that you pull big compressed sets of rows out for aggregation or other operations in big chunks.
Batch mode is a way that operators can work on a “batch” of up to 900 values at a time, instead of working on individual rows. Batch mode can reduce the overhead of metadata and make more efficient use of your CPUs.
Perfmon counters are great for measuring workload, but choosing which counter to baseline can be confusing.
An important query is suddenly slow. Is it because statistics are out of date? This is tricky to figure out, and updating statistics right away can make troubleshooting even harder. Learn how to use query execution plans to get to the heart of the question and find out if stats are really your problem, or if it’s something else.
In this 35 minute episode:
Code samples are at the bottom of the page
They made their index maintenance job smarter, and their queries got slower in production afterward. Could the index maintenance have harmed performance?
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