Re: [HACKERS] idea for 'module' support

Mark Hollomon wrote:

>
>
> As I've been playing with the PL/Perl implementation, it has dawned on me a
> fairly simple, but nice feature could be added.
>
> I would like to add the following command:
>
> LOAD PACKAGE 'package-name';
>
> Like the current 'LOAD' it would treat 'package-name'
> as shared library. But it would also call an intialization function
> in the library (package_init maybe?).
>
> For instance, a user may type:
>
> LOAD PACKAGE 'plperl';
>
> This would not only load the shared library "plperl.so", but call
> the function "package_init" which could the use the SPI facilities
> to properly setup the system tables for the new language.
>
> New types could be packaged the same way.
>
> This would give a very modular way to add 'packages' of functionality.

    1.  All  the functionality required to install such a package
        is only needed once  per  database  (or  if  thrown  into
        template1  once per installation).  But the entire shared
        object has to be linked into each time  a  backend  needs
        one  single function from it. I'm not sure if it's such a
        good idea to  waste  more  and  more  address  space  for
        administrative stuff that isn't required at runtime.

    2.  Most  of such functionality requires PostgreSQL superuser
        rights (like installing C language functions). Thus it is
        useless for a regular user.

    3.  Some  of  the  features might be customizable. Procedural
        languages for example can be installed as trusted ones or
        not. Trusted languages can be used by any regular user to
        CREATE  FUNCTION,  untrusted  ones  can't.  Placing   the
        installation  procedure  inside the module itself doesn't
        make things easier here.


Jan

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