Re: Disallow arrays with non-standard lower bounds

On Mon, Jan 13, 2014 at 10:40:57AM -0600, Merlin Moncure wrote:
> On Sun, Jan 12, 2014 at 4:38 AM, Craig Ringer <craig(at)2ndquadrant(dot)com> wrote:
> > Implicit casts to text, anybody?
>
> This backward compatibility break orphaned the company I work for on
> 8.1 until last year and very nearly caused postgres to be summarily
> extirpated (only rescued at the last minute by my arrival). It cost
> hundreds of thousands of dollars to qualify a sprawling java code base
> so that it could be moved back into a supported version. Breaking
> compatibility sucks -- it hurts your users and costs people money.
> Hacking type casts may not have been a mistake, but the arbitrary
> introduction of the breakage certainly was.

With utmost respect, it was not. Databases are no good if there are
fixable things in them that cause them to produce incorrect results at
random, as auto-casting to text did.

> This project has no deprecation policy,

I believe it actually does, although it's not a formal, written
policy. Would you like to help draft one up?

> and I'd argue we'd need one
> before considering breaking changes. For example, maybe we could pull
> out an occasional release for longer term support to help users that
> caught out. But really, the better way to go IMNSHO is to take a
> hard line on compatibility issues pretty much always -- consider the
> case of libc and win32 api.

Could you please help remind us what that was?

> There are certain limited exceptions to this rule -- for example
> security problems

Probably not.

> or gross violations of the standard

We're definitely there on lower bounds of arrays. The standard, for a
wonder, is clear and unambiguous about them. Whether we should go
there on the rest of our array implementation is a question for
another thread.

Cheers,
David.
--
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