[OPEN-ILS-GENERAL] Upgrade Script for 2.6.4 to 2.7

[Chris Sharp]

Galen,

> - The monolithic scripts allow for consolidating multiple point updates
> into a set of statements that run more quickly.  Arguably this is more of a
> potential for efficiency than something that has always been taken
> advantage of -- but sometimes, it has.
> - Of more import, since the monolithic scripts wrap all of the changes in
> one or two transactions, if something goes wrong, the transaction rolls
> back and the schema remains in a state that corresponds to a released
> version.  In contrast, if something goes wrong while going through a
> sequence of point upgrades and one gets stuck, the database could be in a
> state that doesn't correspond with *any* released version -- which could be
> awkward if one is nearing the end of a maintenance window.  Then again, if
> one hasn't done a dry run first...

Yeah, I can see the advantage of the full rollback.  I wonder if the wrapper/controller script I'm imagining (and Mike mentions in his "steps to make this actually happen" response could have some sort of rollback option (though I know it's Postgres transactions that we depend on for rollback at this point).

> I should emphasize I'm listing some reasons why the monolithic scripts have
> existed -- I'm not suggesting that they're always superior to other
> approaches.

Understood, thanks!

-- 
Chris Sharp
PINES System Administrator
Georgia Public Library Service
1800 Century Place, Suite 150
Atlanta, Georgia 30345
(404) 235-7147
csharp at georgialibraries.org
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