diff options
| author | Georgi Kodinov <kgeorge@mysql.com> | 2008-07-30 14:07:37 +0300 |
|---|---|---|
| committer | Georgi Kodinov <kgeorge@mysql.com> | 2008-07-30 14:07:37 +0300 |
| commit | ae4a35fd5cba393f5e924241b21a7a59fc921b15 (patch) | |
| tree | 9a3ca37f325646d96b550afd705ade75dc8b3d5e /mysql-test/t/func_if.test | |
| parent | 7f615b2c14d3c8d7b7fbd777faa0adeba9a35fdc (diff) | |
| download | mariadb-git-ae4a35fd5cba393f5e924241b21a7a59fc921b15.tar.gz | |
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
Diffstat (limited to 'mysql-test/t/func_if.test')
| -rw-r--r-- | mysql-test/t/func_if.test | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/mysql-test/t/func_if.test b/mysql-test/t/func_if.test index 5373ca3fec6..8da10f36cbe 100644 --- a/mysql-test/t/func_if.test +++ b/mysql-test/t/func_if.test @@ -108,3 +108,46 @@ drop table t1; 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 |