Re: checking for Berkley db 4.2 --> 4.3 upgrade

[Stepan Kasal]

Hi,

On Thu, Jul 14, 2005 at 12:19:26PM -0400, Sam Steingold wrote:
> > * David Boreham <address@hidden> [2005-07-14 08:42:46 -0700]:
> > Wouldn't it be easier to simply read the version number ?
... 
> isn't the whole idea of autoconf to avoid relying on version numbers?

no, it isn't, thought it might sound so.

Yes, you hear "test for features, not for version numbers".
The reasoning is like this:
Say that you observe a bug in latest "Fumix 7.1", which needs a workaround.
If you activate the workaround for Fumix >= 7.1, you might loose in several
cases:
 1) if "Fumix 7.2" will fix the bug
 2) if you encounter a patched version of "Fumix 7.1" which no longer has the 
bug
 3) if "Fumiris 2.0" will have the same bug

So if we speak about a general feature, it's better to test for the feature
then to collect version intervals.

But if you want to use a function from a particular project, it's more safe to
use version numbers:
 ad 1) Future versions will probably still have the funtion.
 ad 2) Older versions don't have it.
 ad 3) If another project provides the same functionality, your build scripts
       wouldn't be able to use it.

Well, instead of a conclusion I have to ask: is "Berkeley db" functionality
available only from one project, or are there several implementations?
(I think the db _format_ can be accessed by several independent libraries,
but that's not the question.)

Hope this sheds some light,
        Stepan