AntDB-Oracle Compatibility Developer’s Manual P3–53

COVAR_POP

Calculate the covariance.

Example:

SELECT MGR , COVAR_POP ( SYSDATE - HIREDATE , sal )  AS covar_pop ,
COVAR_SAMP ( SYSDATE - HIREDATE , sal )  AS covar_samp
FROM emp GROUP BY MGR ORDER BY MGR , covar_pop , covar_samp ;

 MGR  |     COVAR_POP     |     COVAR_SAMP     
------+-------------------+---------------------
 7566 |                 0 |                  0
 7698 |             43976 |              54970
 7782 |                 0 |                   
 7788 |                 0 |                   
 7839 | 10547.22222222222 | 15820.833333333332
 7902 |                 0 |                  0
      |                 0 |                   
(7 rows)

COVAR_SAMP

Calculate the sample covariance.

Example:

SELECT MGR , COVAR_SAMP( SYSDATE - HIREDATE , sal )  AS covar_pop ,
COVAR_SAMP ( SYSDATE - HIREDATE , sal )  AS covar_samp
FROM emp GROUP BY MGR ORDER BY MGR , covar_pop , covar_samp ;

 MGR  |     COVAR_POP      |     COVAR_SAMP     
------+--------------------+---------------------
 7566 |                  0 |                  0
 7698 |              54970 |              54970
 7782 |                    |                   
 7788 |                    |                   
 7839 | 15820.833333333332 | 15820.833333333332
 7902 |                  0 |                  0
      |                    |                   
(7 rows)