Alvaro Herrera <alvherre@commandprompt.com> writes:
> Another change that could be done to Dllist is removing the Dllist
> pointer from the Dlelem struct:
I think this is a bad idea. The patch you propose makes
CatCacheRemoveCTup significantly more expensive (extra hash
calculation). Moreover, the savings involved is entirely illusory:
palloc chunks are powers of 2, therefore 3 pointers take the same
space as 4.
regards, tom lane