Comments on: MySQL Cluster and Codd’s Rule 11

By: Alex Gorbachev

Alex Gorbachev — Mon, 12 Feb 2007 14:22:52 +0000

Actually, in Oracle you can create union view over parts of different tables via database links and make it updatable with INSTEAD OF triggers.
In many cases performance will be far from optimal but it’s doable. :)

By: Noons

Noons — Sun, 11 Feb 2007 22:22:26 +0000

Agreed. It’s never been very clear what was meant by the “locations” bit, indeed. If only tables, then Oracle was compliant since release 5! But if “portions of tables” is the meaning, then it isn’t compliant.
Still, that mysql feature/ability is something that can be mighty useful to defuse “hot spots”. Or create them…

By: Kevin Closson

Kevin Closson — Sat, 10 Feb 2007 18:16:59 +0000

“locations” (as in rule 11) has never really been that well defined. A lot of folks think table partitioning fits this bill.

By: TT

TT — Sat, 10 Feb 2007 15:05:29 +0000

Ehh…. Ericsson sold the cluster software to MySQL and started using Oracle…

By: William Robertson

William Robertson — Sat, 10 Feb 2007 10:02:25 +0000

Does Rule 11 actually require the ability to distribute portions of a table in separate databases in this way? It seems to refer only to “portions of the database” and “various locations”, although to be fair, Dave Ensor’s overview in “Tales of the Oak Table” takes it to mean something similar. As ever, it’s a sketchy definition that leaves you wondering exactly what Codd had in mind. Presumably he wrote more about the subject than twelve vaguely defined rules.
http://en.wikipedia.org/wiki/Codd%27s_12_rules

By: Mr. Ed

Mr. Ed — Sat, 10 Feb 2007 04:24:15 +0000

DB2 DPF does this, too.

I mean, it’d better… Codd worked there!