revision-id: 1aba801dbfc67f788d85faee12189c0e5a6c6c72 (mariadb-10.1.43-215-g1aba801dbfc) parent(s): c400ef2586bd188858ff43f2120fdf17475f2fdb author: Varun Gupta committer: Varun Gupta timestamp: 2020-07-20 16:15:02 +0530 message: MDEV-19232: Floating point precision / value comparison problem The issue occurs when the subquery_cache is enabled. When there is a cache miss the division was leading to a value with scale 9. In the case of cache hit the value returned was of scale 9 and due to the different values for the scales the where condition evaluated to FALSE, hence the output was incomplete. To fix this problem we need to round up the decimal to the limit mentioned in Item::decimals. This would make sure the values are compared with the same scale. --- mysql-test/r/parser_precedence.result | 2 +- mysql-test/r/subselect4.result | 24 ++++++++++++++++++++++++ mysql-test/r/type_newdecimal.result | 5 ----- mysql-test/r/type_ranges.result | 6 ++---- mysql-test/t/subselect4.test | 26 ++++++++++++++++++++++++++ sql/item_func.cc | 2 ++ 6 files changed, 55 insertions(+), 10 deletions(-) diff --git a/mysql-test/r/parser_precedence.result b/mysql-test/r/parser_precedence.result index 4330c8a2045..f23295bd61b 100644 --- a/mysql-test/r/parser_precedence.result +++ b/mysql-test/r/parser_precedence.result @@ -619,7 +619,7 @@ select 4 - 3 * 2, (4 - 3) * 2, 4 - (3 * 2); Testing that / is left associative select 15 / 5 / 3, (15 / 5) / 3, 15 / (5 / 3); 15 / 5 / 3 (15 / 5) / 3 15 / (5 / 3) -1.00000000 1.00000000 9.0000 +1.00000000 1.00000000 8.9998 Testing that / has precedence over | select 105 / 5 | 2, (105 / 5) | 2, 105 / (5 | 2); 105 / 5 | 2 (105 / 5) | 2 105 / (5 | 2) diff --git a/mysql-test/r/subselect4.result b/mysql-test/r/subselect4.result index 22d4938fb78..606ab847028 100644 --- a/mysql-test/r/subselect4.result +++ b/mysql-test/r/subselect4.result @@ -2584,3 +2584,27 @@ l1 i2 e 2 o 6 DROP TABLE t1, t2; +# +# MDEV-19232: Floating point precision / value comparison problem +# +CREATE TABLE t1 (region varchar(60), area decimal(10,0), population decimal(11,0)); +INSERT INTO t1 VALUES ('Central America and the Caribbean',91,11797); +INSERT INTO t1 VALUES ('Central America and the Caribbean',442,66422); +SET @save_optimizer_switch=@@optimizer_switch; +SET optimizer_switch='subquery_cache=on'; +SELECT +population, area, population/area, +cast(population/area as DECIMAL(20,9)) FROM t1 LIMIT 1; +population area population/area cast(population/area as DECIMAL(20,9)) +11797 91 129.6374 129.637400000 +SELECT * FROM t1 A +WHERE population/area = (SELECT MAX(population/area) from t1 B where A.region = B.region); +region area population +Central America and the Caribbean 442 66422 +SET optimizer_switch='subquery_cache=off'; +SELECT * FROM t1 A +WHERE population/area = (SELECT MAX(population/area) from t1 B where A.region = B.region); +region area population +Central America and the Caribbean 442 66422 +SET @@optimizer_switch= @save_optimizer_switch; +DROP TABLE t1; diff --git a/mysql-test/r/type_newdecimal.result b/mysql-test/r/type_newdecimal.result index dc6ef3c59e2..7b6629bc7b2 100644 --- a/mysql-test/r/type_newdecimal.result +++ b/mysql-test/r/type_newdecimal.result @@ -1530,11 +1530,8 @@ select (1.20396873 * 0.89550000 * 0.68000000 * 1.08721696 * 0.99500000 * 1.01500000 * 1.01500000 * 0.99500000) 0.812988073953673124592306939480 create table t1 as select 5.05 / 0.014; -Warnings: -Note 1265 Data truncated for column '5.05 / 0.014' at row 1 show warnings; Level Code Message -Note 1265 Data truncated for column '5.05 / 0.014' at row 1 show create table t1; Table Create Table t1 CREATE TABLE `t1` ( @@ -1649,8 +1646,6 @@ my_col 0.123456789123456789123456789123 DROP TABLE t1; CREATE TABLE t1 SELECT 1 / .123456789123456789123456789123456789123456789123456789123456789123456789123456789 AS my_col; -Warnings: -Note 1265 Data truncated for column 'my_col' at row 1 DESCRIBE t1; Field Type Null Key Default Extra my_col decimal(65,4) YES NULL diff --git a/mysql-test/r/type_ranges.result b/mysql-test/r/type_ranges.result index 101bf0cfb2c..a10d2a56eae 100644 --- a/mysql-test/r/type_ranges.result +++ b/mysql-test/r/type_ranges.result @@ -94,8 +94,6 @@ DROP INDEX test ON t1; insert into t1 values (10, 1,1,1,1,1,1,1,1,1,1,1,1,1,NULL,0,0,0,1,1,1,1,'one','one'); insert into t1 values (NULL,2,2,2,2,2,2,2,2,2,2,2,2,2,NULL,NULL,NULL,NULL,NULL,NULL,2,2,'two','two,one'); insert into t1 values (0,1/3,3,3,3,3,3,3,3,3,3,3,3,3,NULL,'19970303','10:10:10','19970303101010','','','','3',3,3); -Warnings: -Warning 1265 Data truncated for column 'string' at row 1 insert into t1 values (0,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,-1,NULL,19970807,080706,19970403090807,-1,-1,-1,'-1',-1,-1); Warnings: Warning 1264 Out of range value for column 'utiny' at row 1 @@ -136,7 +134,7 @@ select auto,string,tiny,short,medium,long_int,longlong,real_float,real_double,ut auto string tiny short medium long_int longlong real_float real_double utiny ushort umedium ulong ulonglong mod(floor(time_stamp/1000000),1000000)-mod(curdate(),1000000) date_field time_field date_time blob_col tinyblob_col mediumblob_col longblob_col 10 1 1 1 1 1 1 1.0 1.0000 1 00001 1 1 1 0 0000-00-00 00:00:00 0000-00-00 00:00:00 1 1 1 1 11 2 2 2 2 2 2 2.0 2.0000 2 00002 2 2 2 0 NULL NULL NULL NULL NULL 2 2 -12 0.33333333 3 3 3 3 3 3.0 3.0000 3 00003 3 3 3 0 1997-03-03 10:10:10 1997-03-03 10:10:10 3 +12 0.3333 3 3 3 3 3 3.0 3.0000 3 00003 3 3 3 0 1997-03-03 10:10:10 1997-03-03 10:10:10 3 13 -1 -1 -1 -1 -1 -1 -1.0 -1.0000 0 00000 0 0 0 0 1997-08-07 08:07:06 1997-04-03 09:08:07 -1 -1 -1 -1 14 -429496729 -128 -32768 -8388608 -2147483648 -4294967295 -4294967296.0 -4294967295.0000 0 00000 0 0 0 0 0000-00-00 00:00:00 0000-00-00 00:00:00 -4294967295 -4294967295 -4294967295 -4294967295 15 4294967295 127 32767 8388607 2147483647 4294967295 4294967296.0 4294967295.0000 255 65535 16777215 4294967295 4294967295 0 0000-00-00 00:00:00 0000-00-00 00:00:00 4294967295 4294967295 4294967295 4294967295 @@ -188,7 +186,7 @@ Warning 1265 Data truncated for column 'new_field' at row 7 select * from t2; auto string mediumblob_col new_field 1 2 2 ne -2 0.33333333 ne +2 0.3333 ne 3 -1 -1 ne 4 -429496729 -4294967295 ne 5 4294967295 4294967295 ne diff --git a/mysql-test/t/subselect4.test b/mysql-test/t/subselect4.test index b7a9c95abe7..21ec28b1c03 100644 --- a/mysql-test/t/subselect4.test +++ b/mysql-test/t/subselect4.test @@ -2112,3 +2112,29 @@ INSERT INTO t2 VALUES ('k'),('rid'),('f'),('x'); EXPLAIN EXTENDED SELECT * FROM t1 where ( t1.l1 < ANY (SELECT MAX(t2.v1) FROM t2)); SELECT * FROM t1 where ( t1.l1 < ANY (SELECT MAX(t2.v1) FROM t2)); DROP TABLE t1, t2; + +--echo # +--echo # MDEV-19232: Floating point precision / value comparison problem +--echo # + +CREATE TABLE t1 (region varchar(60), area decimal(10,0), population decimal(11,0)); +INSERT INTO t1 VALUES ('Central America and the Caribbean',91,11797); +INSERT INTO t1 VALUES ('Central America and the Caribbean',442,66422); + +SET @save_optimizer_switch=@@optimizer_switch; +SET optimizer_switch='subquery_cache=on'; + +SELECT +population, area, population/area, +cast(population/area as DECIMAL(20,9)) FROM t1 LIMIT 1; + +SELECT * FROM t1 A +WHERE population/area = (SELECT MAX(population/area) from t1 B where A.region = B.region); + +SET optimizer_switch='subquery_cache=off'; +SELECT * FROM t1 A +WHERE population/area = (SELECT MAX(population/area) from t1 B where A.region = B.region); + +SET @@optimizer_switch= @save_optimizer_switch; + +DROP TABLE t1; diff --git a/sql/item_func.cc b/sql/item_func.cc index c41d7809bf9..5e605855d80 100644 --- a/sql/item_func.cc +++ b/sql/item_func.cc @@ -1719,6 +1719,8 @@ my_decimal *Item_func_div::decimal_op(my_decimal *decimal_value) null_value= 1; return 0; } + my_decimal_round(E_DEC_FATAL_ERROR, decimal_value, + decimals, FALSE, decimal_value); return decimal_value; }