4. Reading of datasets from databases
Datasets may be loaded in user-defined buffers or in the Dynamic
Memory (DMM) buffer according to the specifications given by the user
(dataset name, type, length, subset number etc.). The association
between a dataset and an existing or future database is established
when the dataset is defined (unless it is not read in, in which case
its origin is recorded). This is done by specifying the database
handle to which the set may be saved. Only datasets flagged as active
can be written back to the databases. Databases are thus protected
from accidental overwriting.
