mariadb/mysql-test/r/udf.result
evgen@moonbone.local 4ee2e07cc0 Fixed bug#19862: Sort with filesort by function evaluates function twice
When there is no index defined filesort is used to sort the result of a
query. If there is a function in the select list and the result set should be
ordered by it's value then this function will be evaluated twice. First time to
get the value of the sort key and second time to send its value to a user.
This happens because filesort when sorts a table remembers only values of its
fields but not values of functions.
All functions are affected. But taking into account that SP and UDF functions
can be both expensive and non-deterministic a temporary table should be used 
to store their results and then sort it to avoid twice SP evaluation and to 
get a correct result.

If an expression referenced in an ORDER clause contains a SP or UDF 
function, force the use of a temporary table.

A new Item_processor function called func_type_checker_processor is added
to check whether the expression contains a function of a particular type.
2006-07-26 00:31:29 +04:00

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drop table if exists t1;
CREATE FUNCTION metaphon RETURNS STRING SONAME "UDF_EXAMPLE_LIB";
CREATE FUNCTION myfunc_double RETURNS REAL SONAME "UDF_EXAMPLE_LIB";
CREATE FUNCTION myfunc_nonexist RETURNS INTEGER SONAME "UDF_EXAMPLE_LIB";
ERROR HY000: Can't find function 'myfunc_nonexist' in library
CREATE FUNCTION myfunc_int RETURNS INTEGER SONAME "UDF_EXAMPLE_LIB";
CREATE FUNCTION sequence RETURNS INTEGER SONAME "UDF_EXAMPLE_LIB";
CREATE FUNCTION lookup RETURNS STRING SONAME "UDF_EXAMPLE_LIB";
CREATE FUNCTION reverse_lookup
RETURNS STRING SONAME "UDF_EXAMPLE_LIB";
CREATE AGGREGATE FUNCTION avgcost
RETURNS REAL SONAME "UDF_EXAMPLE_LIB";
select myfunc_double();
ERROR HY000: myfunc_double must have at least one argument
select myfunc_double(1);
myfunc_double(1)
49.00
select myfunc_double(78654);
myfunc_double(78654)
54.00
select myfunc_nonexist();
ERROR 42000: FUNCTION test.myfunc_nonexist does not exist
select myfunc_int();
myfunc_int()
0
select lookup();
ERROR HY000: Wrong arguments to lookup; Use the source
select lookup("127.0.0.1");
lookup("127.0.0.1")
127.0.0.1
select lookup(127,0,0,1);
ERROR HY000: Wrong arguments to lookup; Use the source
select lookup("localhost");
lookup("localhost")
127.0.0.1
select reverse_lookup();
ERROR HY000: Wrong number of arguments to reverse_lookup; Use the source
select reverse_lookup("127.0.0.1");
select reverse_lookup(127,0,0,1);
select reverse_lookup("localhost");
reverse_lookup("localhost")
NULL
select avgcost();
ERROR HY000: wrong number of arguments: AVGCOST() requires two arguments
select avgcost(100,23.76);
ERROR HY000: wrong argument type: AVGCOST() requires an INT and a REAL
create table t1(sum int, price float(24));
insert into t1 values(100, 50.00), (100, 100.00);
select avgcost(sum, price) from t1;
avgcost(sum, price)
75.0000
delete from t1;
insert into t1 values(100, 54.33), (200, 199.99);
select avgcost(sum, price) from t1;
avgcost(sum, price)
151.4367
drop table t1;
select metaphon('hello');
metaphon('hello')
HL
CREATE PROCEDURE `XXX1`(in testval varchar(10))
begin
select metaphon(testval);
end//
call XXX1('hello');
metaphon(testval)
HL
drop procedure xxx1;
CREATE PROCEDURE `XXX2`()
begin
declare testval varchar(10);
set testval = 'hello';
select metaphon(testval);
end//
call XXX2();
metaphon(testval)
HL
drop procedure xxx2;
CREATE TABLE bug19904(n INT, v varchar(10));
INSERT INTO bug19904 VALUES (1,'one'),(2,'two'),(NULL,NULL),(3,'three'),(4,'four');
SELECT myfunc_double(n) AS f FROM bug19904;
f
49.00
50.00
NULL
51.00
52.00
SELECT metaphon(v) AS f FROM bug19904;
f
ON
TW
NULL
0R
FR
DROP TABLE bug19904;
create table t1(f1 int);
insert into t1 values(1),(2);
explain select myfunc_int(f1) from t1 order by 1;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE t1 ALL NULL NULL NULL NULL 2 Using temporary; Using filesort
drop table t1;
End of 5.0 tests.
DROP FUNCTION metaphon;
DROP FUNCTION myfunc_double;
DROP FUNCTION myfunc_nonexist;
ERROR 42000: FUNCTION test.myfunc_nonexist does not exist
DROP FUNCTION myfunc_int;
DROP FUNCTION sequence;
DROP FUNCTION lookup;
DROP FUNCTION reverse_lookup;
DROP FUNCTION avgcost;