Suya Huang <shuang@connexity.com> writes:
> Thank you Tom very much, that’s the piece of information I miss.
> So, should I expect that the nested loop join would be much faster if I cache both tables (use pg_prewarm) into
memoryas it waives the disk read?
pg_prewarm is not going to magically fix things if your table is bigger
than RAM, which it apparently is.
regards, tom lane