Xinyi Zou 34bfc42986 [Bug] Fix row_number and group by are inconsistent with 0 and -0 partition (#5226) ...

The essence of the problem is behavior of negative zero (- 0.0) in comparison with positive zero (+ 0.0).
Currently in GroupBy and HashPartition, -0.0 is not equal to 0.0 (result of Hash function),
so the -0.0 and 0.0 are divided into 2 partitions.

In row_number analytic function, for the sorted data, a new partition will be opened when the values ​​​​of
the upper and lower rows are not equal. But in C++ the comparison 0.0 == -0.0 is true, so 0.0 and -0.0
are divided into the same partition for row_number.

(Floating point arithmetic in C++ is often IEEE-754. This norm defines two different representations for
the value zero: positive zero and negative zero. It is also defined that those two representations must
compare equals. Refer to https://stackoverflow.com/questions/45795397)

2021-01-23 21:08:43 +08:00

..

src

[Bug] Fix row_number and group by are inconsistent with 0 and -0 partition (#5226)

2021-01-23 21:08:43 +08:00

test

[Performance Improve] Push Down _conjunctf of 'not in' and '!=' to Storage Engine. (#5207)

2021-01-23 21:07:01 +08:00

CMakeLists.txt

add as sdk to thirdparty (#5234)

2021-01-20 10:51:22 +08:00