On Fri, May 04, 2007 at 03:42:45PM -0400, Tom Lane wrote: > It's hardly credible that you could do either strcmp or strcoll in 2 nsec > on any run-of-the-mill hardware. What I think is happening is that the > compiler is aware that these are side-effect-free functions and is > removing the calls entirely, or at least moving them out of the loops; > these times would be credible for loops consisting only of an increment, > test, and branch.
It's not the compiler, it's the C library. strcmp and strcoll are
defined as:
extern int strcoll (__const char *__s1, __const char *__s2)
__THROW __attribute_pure__ __nonnull ((1, 2));
In this context "pure" is essentially what IMMUTABLE is in postgres.
Which doesn't change the fact that strcoll is expensive.
Have a nice day,
--
Martijn van Oosterhout <[EMAIL PROTECTED]> http://svana.org/kleptog/
> From each according to his ability. To each according to his ability to
> litigate.
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