Using ASF › The Structure and Functions of ASF › Definition

Definition

Applications are developed through ASF by defining data tables. Data tables can be defined easily by all users through the basic definition screens. ASF also provides extended definition screens for use by data processing professionals.

Two Basic Definition Screens

The following basic definition screens are always used in defining a data table:

• Table Definition (TDEF) allows the user to:
  • Specify the type of table being defined: STORED or VIEW
  • Specify a simple table derivation to define a view
  • GENERATE the table and an application for immediate online use of the table
  • DELETE the table definition, the generated application structures, and, for stored tables, all data stored in the table
• Column Definition (CDEF) allows the user to define each column to be contained in the stored table and specify the characteristics of each column.

Six Extended Definition Screens

The following extended screens are intended primarily for use by data processing professionals in further defining a data table:

• Extended Column Definition (XCOL) allows the user to define additional characteristics for a column and to edit the attributes automatically defined for a column.
• Extended Table Definition (XTAB) allows the user to override the default space allocation for the table, to specify access restrictions to be included in the ASF-created application, to review information, and if necessary, modify information supplied by ASF about the table.
• Extended Table Derivation (XDER) allows the user to perform the following activities:
  • Identify the sources from which a view is being derived
  • Name the owner of the source table or the subschema if the source table was defined through a subschema
  • Specify the conditions on which the source tables are to be joined
• Extended Selection Definition (XSEL) allows the user to specify one or more selection criteria that become part of the table definition and are used as edit criteria for loading and/or displaying data.
• Extended Key Definition (XKEY) allows the user to define keys used to index the table.
• Row-Level Security (RSEC) allows the user to specify the security name for the table and any generic column names.