Re: Number of parameters in a sql function

Looks like this was fixed, because we now generate an error:

test=> create function klasd (int, int, int, int, int, int, int, int,
int) returns int as 'asdf' language 'c';
ERROR: Procedures cannot take more than 8 arguments

"Stan Ng" <stan@squaresoft.com> writes:

I'm running into a limit problem with CREATE FUNCTION. Whenever I exceed
the limit on parameters, somewhere around 12 for me, psql bombs on me
with the "pqReadData() -- backend closed the channel unexpectedly" error
message. Is there any way to increase the parameter limit for
functions?

It shouldn't be letting you get that high; the system limit is 8
parameters for a function. (It looks to me like parse_func.c should
be, but is failing to, verify that the length of the parameter lists
it is passed are within bounds --- or else gram.y itself should complain
if the list is overlength.)

Increasing the limit would be rather a major project I suspect.
A quick look around the sources found a lot of dependencies, some
being symbolic constants (not all the same one :-() and some being
hard coded "8"s. Ick. Also, you would certainly be facing an initdb
and database reload, because the number of argument-type columns in
pg_proc would have to increase.

It'd be good to clean this up and replace pg_proc's fixed-size
proargtypes column with a variable-size "array of oid" column.
Any volunteers?

regards, tom lane

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Bruce Momjian <maillist@candle.pha.pa.us> writes:

Looks like this was fixed, because we now generate an error:
test=> create function klasd (int, int, int, int, int, int, int, int,
int) returns int as 'asdf' language 'c';
ERROR: Procedures cannot take more than 8 arguments

I'm not sure if this is a sufficient defense or not --- IIRC, there were
places in the parser that stuffed info into size-8 arrays without any
nearby check that no more than 8 items would be forthcoming. Offhand
the obvious try doesn't crash it:

regression=> select foo(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18);
ERROR: No such function 'foo' with the specified attributes

but I am hoping to go back and look more carefully.

regards, tom lane

Offhand the obvious try doesn't crash it:

regression=> select foo(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18);
ERROR: No such function 'foo' with the specified attributes

SQL functions do allow more than 8 parameters.

Andreas