Michael Glaesemann wrote:
On Sep 6, 2007, at 10:53 , Mark Mielke wrote:
I don't like the truncating hash suggestion because it limits the ability of a hash code to uniquely identify a key.
AIUI, a hash can't be used as a unique identifier: it always needs to be rechecked due to the chance of collisions. There might be other issues with truncation, but preventing hashes from being unique isn't one of them.

Of course - that's why I used the word "limit".

Hash works best, when the key is unique, however. A 32-bit hash will be many powers of 2 more unique than a 8-bit hash.

Cheers,
mark

--
Mark Mielke <[EMAIL PROTECTED]>

---------------------------(end of broadcast)---------------------------
TIP 3: Have you checked our extensive FAQ?

              http://www.postgresql.org/docs/faq

Reply via email to