SQL Server Execution Plans - Grant Fritchey - SQLServerCentral.com

Chapter 5: Controlling Execution Plans with HintsFigure 5.9This query executes a little faster than the original but did we solve our read problem?Table 'Worktable'. Scan count 2, logical reads 17…Table 'ProductModelIllustration'. Scan count 1, logical reads 2…Table 'Product'. Scan count 1, logical reads 15…Table 'ProductModel'. Scan count 1, logical reads 14…Table 'Illustration'. Scan count 1, logical reads 3…Listing 5.12We've re-introduced a worktable, but it does appear that we've eliminated the largenumber of reads. We may have a solution. However, before we conclude the experiment,we may as well as try out the HASH JOIN hint, to see what it might do.OPTION ( HASH JOIN );Listing 5.13We're back to a simplified execution plan using a Hash Match join operation, ascompared to the Merge Join. The execution time is about half what the Merge Join was,and a third of the original query and the I/O looks as shown in Listing 5.14.188