Robert Haas <robertmhaas@gmail.com> writes:
> On Fri, Jan 7, 2011 at 8:20 PM, Tom Lane <tgl@sss.pgh.pa.us> wrote:
>> Between
>> amclusterable, amsearchnulls, and amoptionalkey, I believe that we have
>> quite enough flags already to cover what anything else actually
>> needs-to-know about the AM's behavior.
> I've pretty much come to the conclusion that pg_am is much better at
> providing the illusion of abstraction than it is at providing actual
> abstraction. IIUC, the chances that a third-party AM would need to
> patch core are nearly 100% anyway, so I'm not inclined to spend much
> mental energy trying to figure out what flags it might hypothetically
> need.
Well, I'll grant that allowing loadable modules to emit and replay WAL
records is an unsolved problem, but the existence of that problem
doesn't mean that we should entirely give up on keeping AMs modular.
I believe that they *are* pretty modular except for that one issue.
regards, tom lane