I'm trying to compare the two execution plans (exhaustive search and geqo) from the optimizer, but I always get the same plan from both types. These are the variables I use for geqo:
SET geqo = true; SET geqo_threshold = 2;
My queries have 8-12
FROM items involved, so the optimizer would definitely use the geqo algorithm.
I tried to add more variables to my queries to force the optimizer to choose an other plan:
SET geqo_effort = 2; SET geqo_pool_size = 2; SET geqo_generations = 1;
But like I said, I always get the same plan as the plan from exhaustive search.
Is there any possibility to show which algorithm (exhaustive search or geqo) the optimizer used to create the execution plan? Or are there other ways to force the optimizer to use geqo?