Peter Eisentraut <peter_e@gmx.net> writes:
>> Does anyone have any ideas/opinions/statistics on what the performance
>> difference is between the two calling conventions?
> Version 1 is technically slower if you count the number of instructions,
That would be true if you compare version-0-to-version-0 calls (ie,
plain old C function call) to version-1-to-version-1 calling. But
what is actually happening, since everything in the backend assumes
version 1, is that you have version-1-to-version-0 via an interface
layer. Which is the worst of all possible worlds --- you have all
the overhead of a version-1 call plus the interface layer.
regards, tom lane