Re: schema agnostic functions in language sql - Mailing list pgsql-general

From Rob Sargent
Subject Re: schema agnostic functions in language sql
Date
Msg-id 46867210-4a1e-d066-2e63-1d3fe580a733@gmail.com
Whole thread Raw
In response to Re: schema agnostic functions in language sql  ("David G. Johnston" <david.g.johnston@gmail.com>)
List pgsql-general


On 5/15/20 5:16 PM, David G. Johnston wrote:
On Fri, May 15, 2020 at 4:07 PM Rob Sargent <robjsargent@gmail.com> wrote:

I'm terribly sorry:  I needed to add that plpgsql works without any
knowledge of the schema, where as defining a plain sql functions does
not work without schema qualification.

You need to distinguish between "works" as in "compiles" and "works" as in "executes".

Yes, SQL and pl/pgsql have very different behaviors when it comes to compilation and execution.  In particular SQL performs parsing earlier (during creation - just like it does for views) and links the textual query to its parse result earlier.  For pl/pgsql none of that happens until the function is called.  Because of this pl/pgsql allows for ambiguous sql text to exist and be concretely resolved during execution while SQL does not.

Thank you for the confirmation.  I'll decide whether I move to plpgsql or dither with role/search_path in the db creation scripts.
(Both forms, plpgsql and sql, "work" once given the correct context.)
David J.


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