Re: Everything is now "required by the database system"

On Wed, 2002-08-14 at 00:38, Tom Lane wrote:
> Hannu Krosing <hannu@tm.ee> writes:
> > On Tue, 2002-08-13 at 22:38, Tom Lane wrote:
> >> It's still "extensible", it's just not so easily "contractible"...
> >> 
> >> I'm not sure that this matters, as I've never heard of anyone actually
> >> troubling to remove unused datatypes etc.
> 
> > It could become an issue if PostgreSQL became populat in embedded
> > systems, but then it can of course be done in include/catalog/.
> 
> For an embedded system I'd think you'd want to strip out the support
> code for the unwanted types (ie, the utils/adt/ file(s)), not only the
> catalog entries.  So it's source code changes in any case. The catalog
> entries alone occupy so little space that it's not even worth anyone's
> trouble to remove them, AFAICS.

But if the types themselves were installable, then it would also mean
that unneeded utils/adt/ code would not be installed without need.

> > Probably every type not used in system tables themselves could be made
> > loadable after initdb.
> 
> It certainly *could* be done.  Whether it's worth the trouble is highly
> doubtful.  I'd also be concerned about the performance hit (loadable
> functions are noticeably slower than built-ins).

Really ?

How much is the performance hit ?

Is it unavaoidable ? 

Is it the same on all systems ?

Is it the same for both new and old style C functions ?

Is the performance hit only the first time (when function is loaded) or
every time ?

> Again, when was the last time you heard of anyone actually bothering to
> remove built-in entries from pg_proc or pg_type?

I have sometimes removed _my_own_ unused types/functions before shipping
a product ;)

> I can't see expending a considerable amount of work on a "feature" that
> no one will use.

Sure.

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Hannu