Re: Proposal: Document ABI Compatibility

On Jun 3, 2024, at 5:56 PM, Andres Freund  wrote:

> I don't see how this would trigger random crashes.
> 
> Unfortunately [4] doesn't seem to take me to a relevant message (pruned chat
> history?), so I can't infer more from that context.

You can use [4] to join the Slack (if you haven’t already) and [5] for the relevant post.

> Regardless of ABI issues, it's probably a good idea to continually run tests
> against in-development minor versions, just to prevent something breaking from
> creeping in. IIRC there were a handful of cases where we accidentally broke
> some extension, because they relied on some implementation details.

Oh yeah, I run regular tests against the latest minor release of all supported Postgres version for my extensions, using pgxn-tools[6], which looks like this[7]. Which I consider absolutely essential. But it doesn’t mean that something compiled against .4 will work with .3 and vice versa. That’s what we could use the guidance/guarantees on.

>> Sure, probably not a problem, but if that’s the sole qualifier for making
>> binary changes, I think it’s worth saying, as opposed to “we don’t make
>> any”. Something like “Only changes to padding, which you never used anyway,
>> right?” :-)
> 
> IDK, to me something like this seems to promise more than we actually can.

What I’d like to do is figure out exactly what we *can* promise and perhaps some guidelines, and start with that.

Best,

David

[4]: https://pgtreats.info/slack-invite
[5]: https://postgresteam.slack.com/archives/C056ZA93H1A/p1716502630690559?thread_ts=1716500801.036709&cid=C056ZA93H1A
[6]: https://github.com/pgxn/docker-pgxn-tools
[7]: https://github.com/pgxn/docker-pgxn-tools/actions/runs/9351752462