Part 6 of my series on Craig Freedman’s SQL Server query-processing blog (part 5, October 2006, is here). November 2006 puts the exchange operator from last month to work: how scans, nested loops joins and hash joins actually run in…

Part 5 of my series on Craig Freedman’s SQL Server query-processing blog (part 4, September 2006, is here). October 2006 wraps up the subquery story with decorrelation, answers a reader question about OR-predicates and indexes, and kicks off the parallelism…

Part 4 of my series on Craig Freedman’s SQL Server query-processing blog (part 3, August 2006, is here). September 2006 is aggregation month: how GROUP BY, DISTINCT and the aggregate functions actually execute, plus a closer look at scalar subqueries…

Part 3 of my series on Craig Freedman’s classic SQL Server query-processing blog (part 2, July 2006, is here). August 2006 was join month: the two remaining physical join operators, a summary that pits all three against each other, and…

This is part 2 of my series on Craig Freedman’s classic SQL Server query-processing blog (part 1, June 2006, is here). In July 2006 Craig published four articles that finish the story of indexes and access paths, and then open…

Back in June 2006, Craig Freedman — at the time a developer on the SQL Server query processing team at Microsoft — started a blog about how SQL Server actually executes queries. Almost twenty years later it is still one…