[development] Do not let postgresql hold back great patches

[Chris Johnson]

It's easier to find work-arounds and translations from standard SQL to
MySQL syntax, and do the same thing to translate to another reasonable
database (Posgres, Oracle, MSSQL), than it is to reverse translate
MySQL (or other database) specific features to other databases.

Standard SQL is the sort of the greatest common factor (in the
mathematical sense).  Even more significantly, hundreds of MySQL
people have spent significant effort in coming up with standard SQL
equivalents in MySQL, so most of that work is already done for us.

Maybe there is an open-source tool which can validate standard SQL
which could be used.  Then our DB abstraction could require a
verifiable standard SQL syntax which would then be translated (where
necessary) into the MySQL, Oracle, Postgres, etc. equivalents.   This
might only be for CRUD operations (data manipulation statements) and
not for DDL, for which we already have a reasonable API and which are
much less standardized.

I myself always use MySQL for my Drupal installs -- because it will
work.  Thus, I never test them with Postgres, even though I run
Postgres on several systems, am very comfortable with using it, etc.
I just don't have the time to hassle with discovering some obscure SQL
bug resulting from database incompatabilitilies when I'm just trying
to make a site work.

If I were able to devote more time to just testing Drupal for the sake
of testing it and with no further purpose, I could and would use
Postgres more of the time.  But even then -- if my goal were to test
the new menu code, I'd want to eliminate any other possible error
causing sources, such as using Postgres.

So unless we actually push the issue of supporting multiple databases
as a community, the vast majority of developers will never make the
effort.  And with each passing release spent in that mode, the harder
it will become to reverse it.  We will end up supporting only one
database, MySQL, de facto.