Ulrich <ulrich.mierendorff@gmx.net> writes:
> People say that [EXISTS is faster]
People who say that are not reliable authorities, at least as far as
Postgres is concerned. But it is always a bad idea to extrapolate
results on toy tables to large tables --- quite aside from measurement
noise and caching issues, the planner might pick a different plan when
faced with large tables. Load up a realistic amount of data and then
see what you get.
regards, tom lane