On Oct15, 2011, at 14:52 , Thomas Girault wrote:
Alternatively, we could also set the alpha value before the query :
SELECT set_alpha(0.1); SELECT age, young(age) FROM employees WHERE
young(age);
That's certainly much safer.
I would be very interested to know if there is smarter way to set
On Fri, Oct 14, 2011 at 10:43 AM, Thomas Girault toma.gira...@gmail.com wrote:
I am now trying to limit the number of results in the view according
to the global value K :
CREATE OR REPLACE VIEW filtered_employees AS
SELECT *, get_mu() as mu
FROM employees
ORDER BY mu DESC
On Oct14, 2011, at 16:43 , Thomas Girault wrote:
CREATE OR REPLACE FUNCTION fuzzy2bool(FLOAT)
RETURNS BOOLEAN LANGUAGE SQL AS 'SELECT set_mu($1);SELECT $1 get_alpha()';
It seems dangerous for a cast to modify global state such a MU. The evaluation
order of functions during query execute
Hello,
Thank you for your answer Robert.
Well, SQL, our our dialect of it anyway, doesn't have global
variables. So I think the above is going to throw a syntax error.
You may have global variables in your C code, but those won't be
visible from the SQL level.
I was wrong in the definition
Hello Florian,
It seems dangerous for a cast to modify global state such a MU. The
evaluation
order of functions during query execute isn't always easy to guess, and may
change depending on the execution plan.
I supposed that fuzzy2bool is called just before the terminal evaluation of
the
Hello,
I am writing an extension to easily execute queries with conditions
expressing constraints in fuzzy logics.
I wrote some C functions that get or set global variables in C.
The variables are MU (FLOAT : degree of a fuzzy predicate), ALPHA
(FLOAT : threshold for filtering predicates) and K
