Cartesian Product

How to:

Reference:

Cartesian product enables you to generate a report containing all combinations of non-related records or data instances in a multi-path request. This means that if a parent segment has three child instances on one path and two child instances on another path, when CARTESIAN is ON a request that references the parent segment and both children generates 16 records. When CARTESIAN is OFF, the same request generates only three records.

For related information about controlling how selection tests are applied to child segments on independent paths, see Selecting Records for Your Report.

Syntax: How to Enable/Disable Cartesian Product 

SET CARTESIAN = {OFF|ON}

where:

OFF

Disables Cartesian product. OFF is the default setting.

ON

Enables Cartesian product and generates all possible combinations of non-related records.

SET CARTESIAN may also be issued within a request.

Reference: Usage Notes for Cartesian Product

  • Cartesian product is performed on the lowest segment common to all paths, whether or not a field in that segment is referenced.
  • Short paths do not display in requests with Cartesian product.
  • The SET CARTESIAN parameter is disabled when ACROSS is specified, and a warning message is issued.
  • The SUM display command and the TOT. prefix operator have no effect on Cartesian product.
  • SUM, COMPUTE, and WITHIN in combination with the PRINT display command are performed on the Cartesian product.
  • ON TABLE COLUMN-TOTAL is automatically generated on the Cartesian product.
  • NOSPLIT is disabled if specified in combination with the SET CARTESIAN parameter, and no warning message is issued.
  • MATCH is not supported with the SET CARTESIAN parameter. A warning message is not issued if MATCH is requested, and the request is processed as if CARTESIAN is set to OFF.
  • TABLEF is not supported with the SET CARTESIAN parameter.

Example: Reporting With Cartesian Product

When CARTESIAN is set to ON, the following multi-path request produces a report containing all possible combinations of models and standards for each car: 

SET CARTESIAN=ON
TABLE FILE CAR
PRINT MODEL STANDARD
BY CAR
IF CAR EQ 'JAGUAR'
END

The output in an ASCII environment is: 

CAR
 
MODEL
 
STANDARD
 
JAGUAR
 
V12XKE AUTO
 
4 WHEEL DISC BRAKES
 

                           
V12XKE AUTO

                           
POWER STEERING

                        

                        

                           

                           
V12XKE AUTO

                           
RECLINING BUCKET SEATS

                        

                        

                           

                           
V12XKE AUTO

                           
WHITEWALL RADIAL PLY TIRES

                        

                        

                           

                           
V12XKE AUTO

                           
WRAP AROUND BUMPERS

                        

                        

                           

                           
XJ12L AUTO

                           
4 WHEEL DISC BRAKES

                        

                        

                           

                           
XJ12L AUTO

                           
POWER STEERING

                        

                        

                           

                           
XJ12L AUTO

                           
RECLINING BUCKET SEATS

                        

                        

                           

                           
XJ12L AUTO

                           
WHITEWALL RADIAL PLY TIRES

                        

                        

                           

                           
XJ12L AUTO

                           
WRAP AROUND BUMPERS

                        

                     
                  

               

               
               
When CARTESIAN is set to OFF (the default),
                  the same request results in a report from the CAR data source containing
                  a list of models and standards without logical relationships.
               

               
The output in an ASCII environment is:

               

                  

                     
                        

                           
CAR

                           
MODEL

                           
STANDARD

                        

                        

                           
JAGUAR

                           
V12XKE AUTO

                           
4 WHEEL DISC BRAKES

                        

                        

                           

                           
XJ12L AUTO

                           
POWER STEERING

                        

                        

                           

                           
.

                           
RECLINING BUCKET SEATS

                        

                        

                           

                           
.

                           
WHITEWALL RADIAL PLY TIRES

                        

                        

                           

                           
.

                           
WRAP AROUND BUMPERS