Fast/Unload: Difference between revisions

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'''Fast/Unload''' is a utility whose primary function is to quickly unload data from a
#REDIRECT [[Fast/Unload overview]]
Model 204 data file to one or more sequential data sets.
 
The Fast/Unload utility consists of several functional units. One unit is a data extraction facility which reads data from a ''Model 204'' data file. Another unit is a compiler which converts a special data language describing the output format to machine language. The generated machine language
actually performs the output function. A third unit is a reporting facility which provides a
job log and reports any special conditions or errors that might have occurred during a
run.
 
''Fast/Unload'' can either be invoked directly as a standalone load module or from a User
Language program. When invoked as a standalone load module, ''Fast/Unload''
enqueues the data file in share mode unless explicitly requested otherwise. If the
enqueue fails, ''Fast/Unload'' terminates with an error condition code. It is thus the file
manager's job to ensure that when ''Fast/Unload'' is run as a standalone load module,
''Model 204'' does not have the file to be unloaded locked in exclusive mode.
The ''Fast/Unload User Language Interface'', purchased as a separate Fast/Unload option,
allows one to invoke Fast/Unload using the FastUnload or [[FastUnloadTask method]] of
the [[Recordset class]] or the [[$FunLoad]] function in a User Language program. With this
approach, an application builds a set of records to be unloaded, using standard User
Language statements; for example, you can reduce unload time by restricting the set of
records using indexed Model 204 fields. The Fast/Unload load module runs in a subtask
(or PST under CMS) of Model 204. The Fast/Unload User Language Interface also
provides the ability to unload data from a Model 204 group.
 
With the Fast/Unload User Language Interface, the processing can be performed either
synchronously or asynchronously.
 
A system manager can cancel or examine Fast/Unload requests, and each user can
perform the same functions on asynchronous requests that he or she initiated.
 
See [[List of Fast/Unload $functions]] or the [[FastUnloadTask class]] for more information.

Latest revision as of 18:05, 16 March 2015