Specifying Table Generations

Each of the Identify Table/Row screens will contain a reference to a table generation. This field is used to indicate the generation of the table that is to be browsed or edited.

tableBASE marks each generation of a table that is stored in a library with an absolute generation number from 1-255. The table definition specifies the number of generations to be kept, allowing a maximum of nine generations. Once the maximum number of generations has been reached, storing a new generation causes the oldest generation to be deleted from the library.

A generation can be specified in several ways:

A positive integer refers to an absolute generationnumber.
Generation zero refers to the current generation.
A negative integer refers to a relative generationnumber.
A blank refers to the current generation, which is the default.

For example, if generations 2, 4 and 5 are available, then generation 5 is the current generation.

You can specify either a relative (see Table 123) or an absolute (see Table 124) generation number, refer to:

Table 123. Relative Numbers
Using Relative Numbers	Indicates	Generation
0	5	current
-1	4	one before current
-2	2	two generations back

In the above example of three generations, any other negative integer results in a “Generation not found” message.

Table 124. Absolute Numbers
Using Absolute Numbers	Indicates
5	5
4	4
2	2

Any other positive integer results in a “Generation not found” message.

Note:

Care must be taken when performing data recovery operations. If you have a corrupt generation, for example, generation 0, editing the previous generation (for example, -1) and saving it gives you a valid current generation. During the save, the previously current (and corrupt) generation (0) becomes the previous generation (-1). A safer course of action is to delete the corrupt generation with the tablesONLINE delete table utility.