Re: trouble caused by change in 7.3 handling of ''

Tom Lane wrote:
> Bruce Momjian <pgman@candle.pha.pa.us> writes:
> > I have another interesting idea.  What if we create a postgresql.conf
> > param called prev_compatible that exists in every release.  We default
> > it to false/0.  If it always exists, we can add features under its
> > control even in minor releases.  Most interesting would be to have it be
> > an int and make a bitmask for up to 32 features that could be made
> > backward compatible to the previous release.
>
> Including the definition of the individual bits' behavior?
>
> That strikes me as a mess.  No one could ever be very sure what behavior
> they were getting or not getting by setting such a thing.  But they
> could be quite sure that their code would break in interesting ways in
> the next release.
>
> If we're going to have compatibility flags, they should be clearly
> defined, clearly named, and control just one feature apiece (cf.
> transform_null_equals).

You would define the bits in the release notes.  postgresql.conf only
gets created as part of initdb, and because minor releases don't initdb,
it would be easier to have a single variable that always exists.

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