Perfect statistics histogram in just few steps

Cross post with http://aka.ms/sqlserverteam A similar question about statistics came to the team twice this week: why does updating with fullscan result in fewer histogram steps than when doing a sampled scan? The answer is: the number of histogram steps can be fewer than the number of distinct values. For a histogram with perfect distribution…

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Making parallelism waits actionable

Cross post with http://aka.ms/sqlserverteam During PASS we announced changes to how users will be able to make parallelism waits more actionable – specifically the “infamous” CXPACKET. This change effectively splits CXPACKET waits into an actionable wait (CXPACKET) and a negligible wait (CXCONSUMER). This change will be effective starting with upcoming SQL Server 2017 CU3 and…

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New Showplan enhancements

Cross post with http://aka.ms/sqlserverteam If you follow this blog, you have seen that in the past few releases we have continuously included a number of diagnostic improvements to Showplan. You can read about some of them here. Looking at the actual execution plan is one of the most used performance troubleshooting techniques. Having information on…

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