The following bug has been logged online:

Bug reference: 2647
Logged by:
Email address: postgresql_atomicity (AT) yahoo (DOT) com
PostgreSQL version: 8.1
Operating system: Debian GNU/Linux
Description: Atomicity issues when using rules
Details:

When I ensure atomicity by locking tables in a transaction, my transactions
still break when I have additional tables touched by rules on tables I
explicitly locked. I can work around by also locking them, but this breaks
modularity of the rules. There should be the policy, or at least the option
when creating the rule of also locking the referenced tables of the rules
automatically when locking the table on which the rule was defined.

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