mysql并行

开启或关闭并行查询
开启并行查询
SELECT /*+PARALLEL(x)*/ ... FROM ...;
SELECT /*+ SET_VAR(max_parallel_degree=n) */ * FROM ...
关闭并行查询
SELECT /*+NO_PARALLEL()*/ ... FROM ...;
SELECT /*+ SET_VAR(max_parallel_degree=0) */ * FROM ...