ALTER and VIRTUAL Data Sets

Refer to the DATABridge Programmer’s Reference for instructions on creating ALTER or VIRTUAL data sets.

ALTER Data Set

Use the ALTER declaration when you want to reformat data items in a data set to different layouts (i.e., data item conversion). If you are using DATABridge Clients, however, it is often less expensive to use the date formats provided by the DATABridge Client software. Common uses of the ALTER declaration include the following:

  • Subdividing items
  • If the target database is a relational database, keep in mind that there is often a limit on the number of columns.
  • Merging adjacent items
  • The items must be adjacent and they must be from the same parent group.
  • Formatting dates that cannot be done with the ALTER REDEFINE

VIRTUAL Data Set

VIRTUAL data sets appear as normal data sets to Accessories but do not actually exist in the DMSII database. VIRTUAL data sets allow you to create a structure that doesn’t physically reside in the DMSII database, but one that will be passed to the DATABridge Accessories.