Optimizer Recipes

Every SQL query passes a series of optimizer steps to arrive at a more efficient execution plan. The steps taken are denoted as a 'optimizer pipe' identified by a name, e.g. default_pipe. The active pipe is denoted by the SQL global variable called, e.g.

sql>select optimizer;
+--------------+
| single_value |
+==============+
| default_pipe |
+--------------+
1 tuple (0.863ms)