Re: Extending PostgreSQL with a Domain-Specific Language (DSL) - Development

On Tue, Jul 9, 2019 at 5:23 PM Tom Mercha <mercha_t(at)hotmail(dot)com> wrote:

>
> I understand that you never wrote any PL handler but was just thinking
> about this functionality as a follow-up to our conversation. I was just
> wondering whether anonymous DO blocks *must* return void or not?
>
> The docs for DO say it is a function returning void -
> https://www.postgresql.org/docs/current/sql-do.html

>

But the docs for CREATE LANGUAGE's INLINE HANDLER say 'typically return
> void' - https://www.postgresql.org/docs/current/sql-createlanguage.html

No, the language cannot override the SQL execution environment's
limitations.

"The code block is treated as though it were the body of a function with no
parameters, returning void. It is parsed and executed a single time."

The above applies regardless of the language the code block is written in.

It can, however, affect permanent session state (so, use tables).

David J.