Re: Idea for cleaner representation of snapshots

Gregory Stark <stark@enterprisedb.com> writes:
> It sounds like a fine idea from the point of view of flexibility. But as far
> as faster... I guess it depends on how often HeapTupleSatisfiesVisibility is
> used in contexts where the compiler is able to optimize away the conditionals
> or the cpu is able to predict them accurately.

The compiler can't optimize away those conditionals, and even if the
hardware can predict them accurately, one predicted jump has to be
faster than five successive ones.  The branch-prediction hardware works
for function pointer calls too (else C++ would be seriously slow).
        regards, tom lane