As an initial attempt to try hands-on with postgresql, I've learned on user
created functions and some other internals of postgresql.
Few materials on postgresql indicate that the aggregate functions are slow
due to some internal reasons (index covering, null etc).
I'm looking forward to
I've come across lookup tables, Hamming weights and Brain Kernighan's Algo.
Are they used (combined or separately) in bitmap counting?
Where can I find the coding and please explain the flow a count function
(for a bit counting) via coding rather than the high level architectural
diagrams (which
