Narendra Pradeep U U <narendra(dot)pradeep(at)zohocorp(dot)com> writes:
> Recently I came across a case where the planner choose larger table on hash side. I am not sure whether it is an intended behavior or we are missing something.
Probably the reason is that the smaller table has a less uniform
distribution of the hash key. You don't want to hash with a nonuniform
distribution of the hashtable key; if many keys go into the same bucket
then performance degrades drastically.
regards, tom lane