mariadb/mysql-test/t/func_if.test
Georgi Kodinov ae4a35fd5c Bug#37662 nested if() inside sum() is parsed in exponential time
min() and max() functions are implemented in MySQL as macros.
This means that max(a,b) is expanded to: ((a) > (b) ? (a) : (b))
Note how 'a' is quoted two times.
Now imagine 'a' is a recursive function call that's several 10s of levels deep.
And the recursive function does max() with a function arg as well to dive into
recursion.
This means that simple function call can take most of the clock time.
Identified and fixed several such calls to max()/min() : including the IF() 
sql function implementation.

mysql-test/r/func_if.result:
  Bug#37662 test case
mysql-test/t/func_if.test:
  Bug#37662 test case
sql/item.cc:
  Bug#37662 don't call expensive functions as arguments to min/max
sql/item_cmpfunc.cc:
  Bug#37662 don't call expensive functions as arguments to min/max
sql/item_func.cc:
  Bug#37662 don't call expensive functions as arguments to min/max
2008-07-30 14:07:37 +03:00

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3.8 KiB
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#
# Init section
#
--disable_warnings
drop table if exists t1;
--enable_warnings
#
# Simple IF tests
#
select IF(0,"ERROR","this"),IF(1,"is","ERROR"),IF(NULL,"ERROR","a"),IF(1,2,3)|0,IF(1,2.0,3.0)+0 ;
#
# Test of IF and case-sensitiveness
#
CREATE TABLE t1 (st varchar(255) NOT NULL, u int(11) NOT NULL) ENGINE=MyISAM;
INSERT INTO t1 VALUES ('a',1),('A',1),('aa',1),('AA',1),('a',1),('aaa',0),('BBB',0);
select if(1,st,st) s from t1 order by s;
select if(u=1,st,st) s from t1 order by s;
select if(u=1,binary st,st) s from t1 order by s;
select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
explain extended select if(u=1,st,binary st) s from t1 where st like "%a%" order by s;
#
# NULLIF test
#
select nullif(u, 1) from t1;
explain extended select nullif(u, 1) from t1;
drop table t1;
select nullif(1,'test');
#
# Bug 2629
#
select NULLIF(NULL,NULL), NULLIF(NULL,1), NULLIF(NULL,1.0), NULLIF(NULL,"test");
select NULLIF(1,NULL), NULLIF(1.0, NULL), NULLIF("test", NULL);
#
# Problem with IF()
#
create table t1 (num double(12,2));
insert into t1 values (144.54);
select sum(if(num is null,0.00,num)) from t1;
drop table t1;
create table t1 (x int, y int);
insert into t1 values (0,6),(10,16),(20,26),(30,10),(40,46),(50,56);
select min(if(y -x > 5,y,NULL)), max(if(y - x > 5,y,NULL)) from t1;
drop table t1;
#
# BUG#3987
#
create table t1 (a int);
insert t1 values (1),(2);
select if(1>2,a,avg(a)) from t1;
drop table t1;
#
# Bug #5595 NULLIF() IS NULL returns false if NULLIF() returns NULL
#
SELECT NULLIF(5,5) IS NULL, NULLIF(5,5) IS NOT NULL;
#
# Bug #9669 Ordering on IF function with FROM_UNIXTIME function fails
#
CREATE TABLE `t1` (
`id` int(11) NOT NULL ,
`date` int(10) default NULL,
`text` varchar(32) NOT NULL
);
INSERT INTO t1 VALUES (1,1110000000,'Day 1'),(2,1111000000,'Day 2'),(3,1112000000,'Day 3');
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord ASC;
SELECT id, IF(date IS NULL, '-', FROM_UNIXTIME(date, '%d-%m-%Y')) AS date_ord, text FROM t1 ORDER BY date_ord DESC;
DROP TABLE t1;
#
# Test for bug #11142: evaluation of NULLIF when the first argument is NULL
#
CREATE TABLE t1 (a CHAR(10));
INSERT INTO t1 VALUES ('aaa'), (NULL), (''), ('bbb');
SELECT a, NULLIF(a,'') FROM t1;
SELECT a, NULLIF(a,'') FROM t1 WHERE NULLIF(a,'') IS NULL;
DROP TABLE t1;
# End of 4.1 tests
#
# Bug #16272 IF function with decimal args can produce wrong result
#
create table t1 (f1 int, f2 int);
insert into t1 values(1,1),(0,0);
select f1, f2, if(f1, 40.0, 5.00) from t1 group by f1 order by f2;
drop table t1;
#
# Bug#24532 (The return data type of IS TRUE is different from similar
# operations)
#
# IF(x, unsigned, unsigned) should be unsigned.
#
select if(0, 18446744073709551610, 18446744073709551610);
#
# Bug #37662: nested if() inside sum() is parsed in exponential time
#
CREATE TABLE t1(a DECIMAL(10,3));
# check : should be fast. more than few secs means failure.
SELECT t1.a,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,
IF((ROUND(t1.a,2)=1), 2,0)))))))))))))))))))))))))))))) + 1
FROM t1;
DROP TABLE t1;
--echo End of 5.0 tests