Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]
Groups > comp.lang.php > #6311
| From | "Peter H. Coffin" <hellsop@ninehells.com> |
|---|---|
| Newsgroups | comp.lang.php |
| Subject | Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? |
| Date | 2012-06-12 14:26 -0500 |
| Organization | A noiseless patient Spider |
| Message-ID | <slrnjtf5vi.h39.hellsop@nibelheim.ninehells.com> (permalink) |
| References | <b3a88b31-765b-4537-adfd-563c4734c66a@googlegroups.com> <jr627b$aqj$1@dont-email.me> <a3acc71e-a388-47ed-97c5-72f4d04c40e5@googlegroups.com> |
On Tue, 12 Jun 2012 11:47:04 -0700 (PDT), kurtk@pobox.com wrote:
>> No, hashes can never guaranteed to be unique.
>
> I opted to use
>
> md5(uniqid());
>
> to create a unique key.
Still not guaranteed to be unique. You've even got a defined 13-hexdigit
space thing what you're hashing. Which means as soon as you've got more
than 4,503,599,627,370,495 entries, you are GUARANTEED a collision. That
seems like a lot, but you're down to a one in a billion shot at a
collision when you've got a few million entries. And everybody knows,
that one in a billion changes turn up nine times in ten.
--
48. I will treat any beast which I control through magic or technology
with respect and kindness. Thus if the control is ever broken, it
will not immediately come after me for revenge.
--Peter Anspach's list of things to do as an Evil Overlord
Back to comp.lang.php | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread
Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? "kurtk@pobox.com" <kurtk@pobox.com> - 2012-06-11 17:16 -0700
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Jerry Stuckle <jstucklex@attglobal.net> - 2012-06-11 20:24 -0400
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? "kurtk@pobox.com" <kurtk@pobox.com> - 2012-06-12 11:47 -0700
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Jerry Stuckle <jstucklex@attglobal.net> - 2012-06-12 15:06 -0400
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? "Peter H. Coffin" <hellsop@ninehells.com> - 2012-06-12 14:26 -0500
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Jerry Stuckle <jstucklex@attglobal.net> - 2012-06-12 19:34 -0400
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Captain Paralytic <paul_lautman@yahoo.com> - 2012-06-13 04:09 -0700
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Goran <goran@nospam.com> - 2012-06-13 13:40 +0200
Re: Is spl_object_hash unique in the SQL sense? Can it be used as a unique SQL db column? Captain Paralytic <paul_lautman@yahoo.com> - 2012-06-19 03:32 -0700
csiph-web