On 3/12/18 13:05, Andres Freund wrote: >> will *not* use JIT, becaue jit_expressions applies at execution time. > Right. It'd be easy to change that so jit_expressions=off wouldn't have > an effect there anymore. But I'm not sure we want that? I don't have a > strong feeling about this, except that I think jit_above_cost etc should > apply at plan, not execution time.
I lean toward making everything apply at plan time. Not only is that easier in the current code structure, but over time we'll probably want to add more detailed planner knobs, e.g., perhaps an alternative cpu_tuple_cost, and all of that would be a planner setting. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services