Re: POC: Sharing record typmods between backends

On 2017-08-11 11:14:44 -0400, Robert Haas wrote:
> On Fri, Aug 11, 2017 at 4:39 AM, Thomas Munro
> <thomas(dot)munro(at)enterprisedb(dot)com> wrote:
> > OK. Now it's ds_hash_table.{c,h}, where "ds" stands for "dynamic
> > shared". Better? If we were to do other data structures in DSA
> > memory they could follow that style: ds_red_black_tree.c, ds_vector.c,
> > ds_deque.c etc and their identifier prefix would be drbt_, dv_, dd_
> > etc.
> >
> > Do you want to see a separate patch to rename dsa.c? Got a better
> > name? You could have spoken up earlier :-) It does sound like a bit
> > like the thing from crypto or perhaps a scary secret government
> > department.

I, and I bet a lot of other people, kind of missed dsa being merged for
a while...

> I doubt that we really want to have accessor functions with names like
> dynamic_shared_hash_table_insert or ds_hash_table_insert. Long names
> are fine, even desirable, for APIs that aren't too widely used,
> because they're relatively self-documenting, but a 30-character
> function name gets annoying in a hurry if you have to call it very
> often, and this is intended to be reusable for other things that want
> a dynamic shared memory hash table. I think we should (a) pick some
> reasonably short prefix for all the function names, like dht or dsht
> or ds_hash, but not ds_hash_table or dynamic_shared_hash_table and (b)
> also use that prefix as the name for the .c and .h files.

Yea, I agree with this. Something dsmhash_{insert,...}... seems like
it'd kinda work without being too ambiguous like dht imo is, while still
being reasonably short.

> Right now, we've got a situation where the most widely-used hash table
> implementation uses dynahash.c for the code, hsearch.h for the
> interface, and "hash" as the prefix for the names, and that's really
> hard to remember. I think having a consistent naming scheme
> throughout would be a lot better.

Yea, that situation still occasionally confuses me, a good 10 years
after starting to look at pg... There's even a a dynahash.h, except
it's useless. And dynahash.c doesn't even include hsearch.h directly
(included via shmem.h)! Personally I'd actually in favor of moving
hsearch.h stuff into dynahash.h and leave hsearch as a wrapper.

- Andres