Tag Archives: Performance

Filesort optimization in 5.7.3: pack values in the sort buffer

In MySQL, filesort is the catch-all algorithm for producing sorted results for ORDER-BY or GROUP-BY queries. MySQL has two algorithms for filesort, both the original and the modified algorithms are described in the user manual.  The most commonly used algorithm is the so called modified algorithm, it is used for all cases except when BLOB and TEXT column are involved.…