[jira] [Created] (MADLIB-1460) Prevent an "integer out of range" exception in linear regression train

["Daniel Daniel (Jira)" <ji...@apache.org>]

Daniel Daniel created MADLIB-1460:
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             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. 

 

 

 



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