David Geier <geidav...@gmail.com> writes: > eqjoinsel() can be optimized by not reading MCV stats if at least one of > the two join attributes is unique.
There won't *be* any MCV stats for a column that ANALYZE perceives to be unique, so I'm not quite sure where the claimed savings comes from. > With this change we saw some queries improve planning time by more than > 2x, especially with larger values for default_statistics_target. Please provide a concrete example. regards, tom lane