How often you see some smartie “optimizes” the query by removing ORDER BY, justifying that query always goes by that index, and index is in desired order for the result? Or they say: “I executed this query thousands of times …
Introduction In our tuning work and often in presentations we see people use SET STATISTICS IO ON as a handy way to measure IO, especially logical reads. But, not many people know that it skips measuring IO from certain types …
Do you measure query IO with SET STATISTICS IO ON ? Read more »
Are you still using READ COMMITTED transaction isolation level? Default transaction isolation level on all SQL Server versions (2000-2014) has serious inconsistency problems, by design. Not many people are familiar how and why is it happening. I am writing this …
Introduction We either have or will experience a drive failure. Doesn’t matter if we talk about HDD, SSD, or PCIe disks, any storage disk drive will fail eventually. But how probable it really is, especially if we have many drives? …
Disk failure probability on a large number of disks Read more »
There are some myths widely spread about transaction log that are to be debunked here: Log backup copies log file FALSE. Someone might think if you have 100GB log, that log backup will also be 100GB, since they think the …
Sometimes we need a low-privileged user to do a specific administration task or task that require some server-level permissions (such as VIEW SERVER STATE, ALTER TRACE etc). Of course, we do not want to give that account server-level privilege, because …
Introduction What is the best practice, how to properly set-up transaction log initial size, growth, and number of VLFs? There are many articles on the net on that theme, and some of them are suggesting really wrong concepts, like setting …
Transaction log truncate – why it didn’t shrink my log ? (Truncate vs Shrink) Introduction One term that makes the most confusion between people dealing with sql server transaction log is “log truncation”. In this article I’ll explain what log …
Transaction log Truncate vs Shrink vs VLF number Read more »
Introduction You got yourself in situation where transaction log has massively grown, disk space became dangerously low and you want a quick way to shrink it before server stops ? There are many articles on the net on that theme, …
Transaction log survival guide: Shrink 100GB log Read more »
