Mysql benchmarking: Difference between revisions
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Latest revision as of 03:11, 7 September 2022
Traps
Caches
See mysql caches.
Tools
Status
SHOW STATUS SHOW SESSION STATUS # low-level info about temp-tables, reads, sorting, etc.Query Processes
processes in
SHOW FULL PROCESSLIST
describe a query's currentstate
.
profiling in mysql shows the time spent in each state of a query.Benchmarker
The benchmark tool repeats a query N times, and gives you the (average?) time to execute.
Beware, this uses the query cache.SELECT BENCHMARK(100, SELECT * FROM foo LIMIT 10); # run query 100x timesProfiler
# enable profiling, and query SET profiling = 1 SELECT SQL_NO_CACHE * FROM footable; # inspect profile results SHOW PROFILES; # list profiled queries, by ID SHOW PROFILE; SHOW PROFILE FOR QUERY 1; # show profile for a specific query-id