mysql查看执行计划

1 以json方式查看执行计划

   explain format=json select * from test;

2trace方式查看执行计划

SET
OPTIMIZER_TRACE="enabled=on",END_MARKERS_IN_JSON=on;

SET
OPTIMIZER_TRACE_MAX_MEM_SIZE=90000000;

select
* from test

select
*
from
information_schema.optimizer_trace\G

3使用workbench的图形化方式