tablesONLINE/ISPF requires detailed information about the format of the tables on which it operates. For example, to display a field, tablesONLINE must know where the data is within a row, the names of the field(s), and whether to interpret the data as text characters, binary integers, dates, or other data types.
This table-defining information is maintained in two places: the Data Table and the View.
Data table characteristics, such as table organization, search method, and row size are stored in a Data Table, which is defined by editing the table-definition block of the Data Table.
Other table-defining information specifies row characteristics and is stored in the View. Rows are defined in tablesONLINE Views.
tablesONLINE sees tables in pairs, each consisting of a Data Table and a View that contains the data definitions. Each table accessed by tablesONLINE must have both a data component and a View component. The name of each Data Table has the format shown in Table 191.
|
Byte Position |
Value |
|---|---|
|
1 |
Uppercase alpha character |
|
2-7 |
Uppercase alpha or numeric character |
|
8 |
Uppercase alpha or numeric character or # |
tablesONLINE automatically generates the View name by changing a bit of the first byte of the Data Table name, resulting in a lowercase letter.
A Data Table may have more than one associated View. Similarly, a View may be associated with more than one Data Table. Each View defines a different perspective of the Data Table. To the user, each View appears as a separate table.
There are three categories of table-defining information: row layout, tablesONLINE system characteristics, and tableBASE table definition.