Nikita Malakhov <hukutoc(at)gmail(dot)com> writes:
> Wanted to ask this since I encountered a need for a cache with 5 keys -
> why is the syscache index still limited to 4 keys?
Because there are no cases requiring 5, so far.
(A unique index with as many as 5 keys seems a bit fishy btw.)
regards, tom lane