Re: contrib loose ends: 9.0 to 9.1 incompatibilities

On Wed, Feb 16, 2011 at 12:31 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
>> The trouble is that we have no mechanism for conditional logic in
>> upgrade scripts, so if the system catalog structure should change in a
>> way that causes the hook and unhook mechanism to require different
>> logic depending on which PG major version is in use, we're hosed.
>
> Well, actually, we *do* have such a mechanism (plpgsql), we just don't
> want to use it unless we have to.  I wouldn't feel too bad about saying
> "upgrading tsearch2 directly from 9.0 to 9.4 requires that you have
> plpgsql installed when you issue the CREATE EXTENSION command".
>
> I grant all your points about abstraction being a good thing.  But there
> are only so many hours in the day, and writing (and then maintaining)
> thousands of lines of C code on the grounds that maybe that will let
> somebody avoid writing some ugly code someday is not going to get to
> the top of my to-do list anytime in the foreseeable future.

Well, it sounds like we're in agreement at least about 9.1, so we can
leave the rest of the argument to another day. I *am* surprised that
you think it would take *thousands* of lines of code.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company