The 'organization' is a value that specifies the file
organization. If you are accessing an existing file, the
specified organization must match the organization of the
existing file; if it does not, an error occurs. The choices for
this parameter are SEQUENTIAL, RELATIVE, and INDEXED. The
default is SEQUENTIAL. The parameter choices are as follows:
o SEQUENTIAL file organization specifies that file components
are stored one after the other, in the order in which they
were entered into the file. VSI Pascal supports this
organization for files on disk. This is the only
organization supported for files on magnetic tape, on
terminals, on card readers, and on line printers.
o RELATIVE file organization consists of a series of
fixed-length component positions (cells) numbered
consecutively from 1 to n. The numbered, fixed-length cells
enable VSI Pascal to calculate the component's physical
position in the file. The cell numbers are called relative
component numbers. VSI Pascal supports this organization on
disk files only.
o INDEXED file organization specifies that, in addition to the
stored components, there exists at least a primary key and
possibly alternate keys (first alternate key, second
alternate key, and so forth). VSI Pascal uses the primary
key to store components and uses a program-specified key or
keys to retrieve data. VSI Pascal supports this
organization on disk files only.