Joe Sack (Joe@SQLskills.com, twitter @josephsack)
is a Principal Consultant, author and trainer at SQLskills.com. Prior to joining SQLskills, Joe worked at Microsoft as a Premier Field Engineer for large enterprise environments. He is a SQL Server MVP and Microsoft Certified Master (MCM) for versions 2005 & 2008. For his last few years at Microsoft, he was responsible for the SQL Server MCM Program (2009 to 2011). He has written
several books, articles and whitepapers including SQL Server 2008 Transact-SQL Recipes (Apress, 2008) and SQL Server 2005 T-SQL Recipes (Apress, 2005).
The Query Optimiser needs a good estimate of the number of rows likely to be returned by each physical operator in order to select the best query plan from the most likely alternatives. Sometimes these estimates can go so wildly wrong as to result in a very slow query. Joe Sack shows how it can happen with SQL Queries on a data warehouse with a star schema.… Read more
SQL Server's 'Semantic Search' feature seemed an exciting feature when first shown. Was it really true that Microsoft had come up with a system to rival the industry-leaders, one that could extract the contextual meaning of terms in text, or automatically categorise the subject matter of text? On first inspection, it seems unlikely.… Read more
If you are trouble-shooting an AlwaysOn Availability Group topology, a study of the wait statistics will give a pointer to many of the causes of problems. Although several wait types are documented, there is nothing like practical experiment to familiarize yourself with new wait stats, and Joe Sack demonstrates a way of testing the sort of waits generated by an availability group under various circumstances.… Read more