[wp-hackers] Time to change GUID to UUID?

Lynne Pope lynne.pope at gmail.com
Fri May 6 04:19:54 UTC 2011

Last year I sought help for a GUID issue that was causing problems on a
client site. I've run into problems again, with another site. GUID's are
supposed to be unchanging, globally unique identifiers. A combination of the
way WordPress GUID's have been written & changed over the years, along with
myriads of, "how to change your domain name via SQL when moving WordPress"
posts around the blogosphere, have resulted in GUID's that are far from

In this database I'm looking at now, there are hundreds of localhost GUID's.
No way are they globally unique. Worse, the domain has changed so feed
readers haven't a hope of knowing if these have been delivered previously.
There are also GUID's that are duplicated and more, due to the blog changing
domains over the years, and the domain part of the GUID being changed
inadvertently with global SQL updates.
Then it has the page GUID's that were generated with just the site_url due
to the auto-draft bug in 3.1.
There's GUID's shown as example.com/?page_id=123,   example.com/?post_id=123,
and   example.com/?p=123 . For some reason, Opera seems to pick up the 123
and treat these as if they were the same content (they are not).   There's
even example.com/2004/123 and example.com/2007/123.
It's a right royal mess but the problem is - their GUID's are not unique,
even within their own domain.

Once upon a time, people didn't often change domains. Having a domain-based
GUID wasn't so silly back then. Today, they do change domains and - worse
still - a lot of inexperienced people run SQL commands to change the URI
globally when moving their sites.

With 3.2 moving to MySQL5 I can't see any reason why GUID's can't be changed
to UUID.

This ticket has been hanging around for 3 years now and was closed with
"won't fix" 6 months ago. http://core.trac.wordpress.org/ticket/6492

Does anyone know why this isn't being changed? Are there only a very few of
us that see non-unique GUID's?


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