Thread

1. Bug in PL/Perl 8.1.3

   Chana Slutzkin <chana@cs.huji.ac.il> — 2006-05-18T12:11:36Z

   In 8.1.3, a PL/Perl function that returns 'SETOF',
   when used in the SELECT list of a query, generates the following error:
   
     "set-valued function called in context that cannot accept a set"
   
   Hence there does not seem to be any way of using a PL/Perl function
   that returns 'SETOF' on non-constant input 
   (e.g. on a set of table rows generated by the FROM clause of a query).
   
   The DNS data for our our network, consisting of several thousand machines, 
   is stored as one row per series of machines.
   I have a PL/Perl function that converts a row of the table
   to a set of composite type, one per machine. 
   It worked fine on 8.0.3.
   
   Below is code that illustrates the problem.
   It shows functions in both SQL and PL/Perl that take as input some table rows 
   and return 'SETOF int'.
   The SQL function works fine on 8.0.3 and 8.1.3.
   The PL/Perl function works fine on 8.0.3.
   The error occurs only for the PL/Perl function on 8.1.3.
   
   -------------------------------------------------------------------------------
   CREATE TABLE mytable (n int);
   COPY mytable FROM stdin;
   1
   2
   3
   \.
   
   CREATE FUNCTION  mysqlfunc(mytable) RETURNS SETOF int AS $$
      SELECT $1.n
   $$ LANGUAGE SQL;
   
   CREATE FUNCTION myperlfunc(mytable) RETURNS SETOF int AS $$
     return [$_[0]->{n}];
   $$ LANGUAGE plperl;
   
   SELECT mysqlfunc(mytable.*) from mytable where n=2;
   SELECT myperlfunc(mytable.*) from mytable where n=2;
   
   -------------------------------------------------------------------------------
   
   With VERBOSITY set to verbose, error message is:
     ERROR:  0A000: set-valued function called in context that cannot accept a set
     LOCATION:  plperl_func_handler, plperl.c:1029
   
   I have tested only on FreeBSD-6.1.
   
   
   	Chana Slutzkin
   	CS System Group
   	Hebrew University
   	Jerusalem, Israel
   
   
   P.S. I posted the bug a few days ago as BUG #2426 but it received no response.
   I hope I have expressed myself more clearly this time.
   
   
   
   
   
   
   

2. Re: Bug in PL/Perl 8.1.3

   Tom Lane <tgl@sss.pgh.pa.us> — 2006-05-18T14:12:13Z

   Chana Slutzkin <chana@cs.huji.ac.il> writes:
   > In 8.1.3, a PL/Perl function that returns 'SETOF',
   > when used in the SELECT list of a query, generates the following error:
   >   "set-valued function called in context that cannot accept a set"
   
   This is a consequence of
   http://archives.postgresql.org/pgsql-committers/2005-06/msg00054.php
   and is not likely to change.  Sorry.
   
   			regards, tom lane