Documentation Home
MySQL 5.7 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr) - 35.1Mb
PDF (A4) - 35.2Mb
Man Pages (TGZ) - 255.8Kb
Man Pages (Zip) - 360.8Kb
Info (Gzip) - 3.4Mb
Info (Zip) - 3.4Mb
Excerpts from this Manual

MySQL 5.7 Reference Manual  /  ...  /  Measuring the Speed of Expressions and Functions

8.13.1 Measuring the Speed of Expressions and Functions

To measure the speed of a specific MySQL expression or function, invoke the BENCHMARK() function using the mysql client program. Its syntax is BENCHMARK(loop_count,expr). The return value is always zero, but mysql prints a line displaying approximately how long the statement took to execute. For example:

Press CTRL+C to copy
mysql> SELECT BENCHMARK(1000000,1+1); +------------------------+ | BENCHMARK(1000000,1+1) | +------------------------+ | 0 | +------------------------+ 1 row in set (0.32 sec)

This result was obtained on a Pentium II 400MHz system. It shows that MySQL can execute 1,000,000 simple addition expressions in 0.32 seconds on that system.

The built-in MySQL functions are typically highly optimized, but there may be some exceptions. BENCHMARK() is an excellent tool for finding out if some function is a problem for your queries.