Re: Enabling Checksums

Jeff Davis wrote:

> And the next question is what commands to add to change state. Ideas:
>
>    CHECKSUMS ENABLE; -- set state to "Enabling"
>    CHECKSUMS DISABLE; -- set state to "Off"
>
> And then to get to the "On" state, you have to run a system-wide VACUUM
> while in the "Enabling" state. Or, if the above syntax causes problems,
> we can make all of these into VACUUM options.

There's no such thing as a system-wide VACUUM.  The most you can get is
a database-wide VACUUM, which means you'd have to store the state
per-database somewhere (presumably the pg_database catalog), and perhaps
pg_control could have it as a system-wide value that's computed as the
minimum of all database states (so it stays "enabling" until all
databases have upgraded to "on").

--
Álvaro Herrera                http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services