Re: Why does the PL/pgSQL compiler do this?

On Mon, Oct 31, 2016 at 3:13 PM, Michael Moore <michaeljmoore@gmail.com> wrote:

Here is the complete function, but all you need to look at is the exception block. (I didn't write this code) :-)  I will ask the question after the code.

​[...]​

        RETURN TRUE;

EXCEPTION WHEN OTHERS THEN

        RAISE EXCEPTION '% %', SQLERRM, SQLSTATE;

        ROLLBACK;

        RETURN FALSE;

END;

$BODY$

  LANGUAGE plpgsql VOLATILE

  COST 100;

So, here is the question. Why does the compiler not catch:

1) ROLLBACK; is not a valid PL/pgSQL command

R

​eading section ​41.10.2 at the linked page should answer this part.

https://www.postgresql.org/docs/current/static/plpgsql-implementation.html

 

2) ROLLBACK; and RETURN FALSE; can never be reached

Similar to the above - though "static analysis" is yet a step beyond even what the syntax checking skipping covered above would reveal.

​David J.​