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