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Data Conversion Cost

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The following list provides advice on selecting the data types that convert most efficiently between Automation and COBOL.

  • If the source and destination data types are not strictly dictated, you can decrease the amount of CPU resource consumed by Transaction Integrator (TI) by appropriately selecting the data conversions that are performed (that is, selecting the source and destination data types wisely).

  • The most efficient way to pass data is to select an Automation type of VT_BYTE and a COBOL data type of PIC X untranslated. There is no conversion performed and the data is copied as is.

  • The Automation type VT_BSTR (a UNICODE character string) converts efficiently to COBOL PIC X. Be aware that a BSTR is not the same as a C character data type; it is a Visual Basic String.

  • The most efficient numeric data type conversions are VT_I2 (Visual Basic Integer or C short) to COBOL PIC S9(4) COMP, and VT_I4 to PIC S9(8) COMP.

  • If the data type you want is a COBOL packed decimal, the best choice for data conversion performance is one of the Automation integer data types. If fractional parts are required (that is, a COBOL picture like PIC S9(5)V99 COMP-3), the best choice for the Automation type is VT_DECIMAL (Decimal) or VT_CY (Currency).

  • When the COBOL data type is zoned decimal (that is, a COBOL picture similar to PIC S9(7)V99 DISPLAY), the same considerations as for packed decimal apply. It is slightly more work to convert Automation data types to and from zoned decimal than it is to perform the conversions to packed decimal. If the data is used in calculations on the mainframe system, it is more efficient to use packed decimal instead of zoned decimal.

  • Converting floating point data types (Automation types VT_R4 and VT_R8) is, in most cases, the most expensive. Converting VT_R4 to a COBOL COMP-1, or VT_R8 to a COBOL COMP-2 (a COBOL floating point number) data type is the most efficient conversion involving floating-point numbers.

See Also

Transaction Integrator Performance Guide