Hi, Please find attached the patch to support ALTER EXTENSION UPGRADE, following exchanges made on this list — we can't really speak about decisions here, apparently, until commit is done :)
The documentation is available online for easy browsing here: http://pgsql.tapoueh.org/extensions/doc/html/extend-extension.html The things we might want to discuss are, AFAIUI: - support for upgrading from pre-9.1 extension, or to get from a bunch of related pl code to a proper extension in your database I've done the code for that to work, the idea is pretty simple and relies on the following points. Please note that the attached patch only implements support for upgrading some contrib modules from pre-9.1, that's because I'm willing to get some approvement before continuing the effort — I foresee no road blocks here. - CREATE WRAPPER EXTENSION If you want to upgrade an extension, it first has to exists as an extension. When you're wanting to switch to extension, you need a way to bootstrap your extension object, because you want an entry in the catalogs and you don't want to run the script: it has already been run before you decided this would make for an extension. This command allows you to register an extension in the catalogs, bypassing any script and forcing the version to NULL. I'm not sold on the 'WRAPPER' keyword here, I just used an existing one in the grammar that looked like a good candidate. This was the best I could find, but IANANS (I am not a native speaker). - ALTER EXTENSION ... UPGRADE This allows you to upgrade an existing extension, wrapper included. The extension author needs to prepare the upgrade scripts, and to setup in the control file which to use. The new extension's version is static as the upgrade files you distribute depend on this (think packaging here) and so you pick the upgrade script file to execute depending only on the currently installed version. This picking is made by regular expression matching (using the code backing the ~(text, text) operator), and supports null as a special case. The first match wins, other candidates are bypassed. - CREATE EXTENSION ... WITH SYSID ... Thinking about upgrades, I added support for that too. This might be necessary for pg_upgrade, but I'm not so sure. It was an experiment but I though we might as well talk about it before I remove it from the patch :) - ALTER OBJECT ... SET EXTENSION ... This implements the magic behind "upgrading from null", as it allows the users to add objects to an existing extension. Internally, this will only record a INTERNAL depedency between the object and the extension. This is mainly for use in upgrade scripts when you support pre-9.1 extension upgrade, or for internal PL code that grows into an extension after the fact. Regards, -- Dimitri Fontaine http://2ndQuadrant.fr PostgreSQL : Expertise, Formation et Support
upgrade_extension.v1.patch.gz
Description: ALTER EXTENSION UPGRADE, patch version 1
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