Daniel Daniel created MADLIB-1460:
-------------------------------------
Summary: Prevent an "integer out of range" exception in linear
regression train
Key: MADLIB-1460
URL: https://issues.apache.org/jira/browse/MADLIB-1460
Project: Apache MADlib
Issue Type: Bug
Components: Module: Linear Regression
Reporter: Daniel Daniel
Linear regression training results in 2 output tables (*neither are optional*):
* The *primary* output table, that includes the computed coefficients.
* A *summary* output table, that contains a single line.
+Scenario+
Running the linear regression training in postgresql on an input table which
has *more than 2^31 records* within it (even if a grouping column is
specified), fails due to an "*integer out of range*" exception.
+Source+
*The summary table* has a column that stores *the total number of records*
involved in the computation. The column's data type is a *singed integer*.
However, the total number of records is computed as a *BIGINT*. Therefore, when
the total number of records in the input table is beyond the range of a signed
integer (i.e., 2^31), an "integer out of range" exception is thrown.
+Solution+
A simple solution is to change the data type of the column from a *signed
integer* into a *BIGINT*.
+Test+
We have executed the linear regression training function with and without the
suggested modification on an input table having between 2^31-2^32 records.
Without the modification, an integer out of range exception was thrown. After
modifying the code as suggested, it worked perfectly.
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
