Oliver Elphick <olly(at)lfix(dot)co(dot)uk> writes:
> execv() is a system call to run another executable in place of the
> current process. If the other executable is not present, or does not
> have permissions, you will not be able to run it. Find out why.
Aside from access problems for the executable itself, it could be that
there's a shared-library access problem. Perhaps ldconfig needs to be
told where libpq.so is?
regards, tom lane