recursive text construction in plpgsql?
The simple recursive function:
--
DROP FUNCTION testRecurse(int,int);
CREATE FUNCTION testRecurse(int,int) RETURNS text AS '
DECLARE
rslt text;
BEGIN
IF $1 = 0 THEN
rslt= CAST($2 AS TEXT);
ELSE
rslt= CAST($1 AS TEXT) || '','' || testRecurse($1 - 1, $2);
END IF;
RETURN rslt;
END;
' LANGUAGE 'plpgsql';
--
does not give the result I expect. For example, for:
SELECT testRecurse(4,3);
it seems to me that the result should be:
4,3,2,1,3
instead of what is returned:
1,1,1,1,3
Is this supposed to work in 7.1.3?
-frank
Frank Miles <fpm@u.washington.edu> writes:
The simple recursive function:
[ doesn't work ]
Hmm. In development sources I get
regression=# SELECT testRecurse(4,3);
NOTICE: Error occurred while executing PL/pgSQL function testrecurse
NOTICE: line 7 at assignment
ERROR: MemoryContextAlloc: invalid request size 2139062147
Looks like you have found a real bug, but I don't know what it is yet...
regards, tom lane
I said:
Frank Miles <fpm@u.washington.edu> writes:
The simple recursive function:
[ doesn't work ]
Looks like you have found a real bug, but I don't know what it is yet...
Now I do :-(. FunctionCache needs to be a read-only data structure;
it can't contain the argument block that's built for an individual call,
because the same expression tree might be invoked recursively while
filling in the arguments for a function. I'm surprised no one has
noticed this before.
I'll fix it for 7.2...
regards, tom lane