Fast/Unload: Difference between revisions

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<var class="product">Fast/Unload</var> 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 <var class="product">Fast/Unload</var> utility consists of several functional units. One unit is a data extraction facility which reads data from a <var class="product">Model 204</var> 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.
<var class="product">Fast/Unload</var> can either be invoked directly as a standalone load module or from a User
Language program. When invoked as a standalone load module, <var class="product">Fast/Unload</var>
enqueues the data file in share mode unless explicitly requested otherwise. If the
enqueue fails, <var class="product">Fast/Unload</var> terminates with an error condition code. It is thus the file
manager's job to ensure that when <var class="product">Fast/Unload</var> is run as a standalone load module,
<var class="product">Model 204</var> does not have the file to be unloaded locked in exclusive mode.
The <var class="product">Fast/Unload User Language Interface</var>, purchased as a separate <var class="product">Fast/Unload</var> option,
allows one to invoke <var class="product">Fast/Unload</var> from User Language,
using the <var>[[FastUnload (Recordset function)|FastUnload]]</var> or <var>[[FastUnloadTask (Recordset function)|FastUnloadTask]]</var> functions of
the <var>[[Recordset class|Recordset]]</var> class or the [[$FunLoad]] function .
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 <var class="product">Model 204</var> fields. The <var class="product">Fast/Unload</var> load module runs in a subtask
(or PST under CMS) of <var class="product">Model 204</var>.
With the <var class="product">Fast/Unload User Language Interface</var>, the processing can be performed either
synchronously or asynchronously.
A system manager can cancel or examine <var class="product">Fast/Unload</var> requests, and each user can
perform the same functions on asynchronous requests that he or she initiated.
To explore the details, see "[[:Category:Fast/Unload User Language Interface|Components]] of the <var class="product">Fast/Unload User Language Interface</var>".
The <var class="product">Fast/Unload User Language Interface</var> also
provides the ability to unload data from a Model 204 group.
The standalone <var class="product">Fast/Unload</var> load module
can also unload a group of files, although without access to group definitions in <var class="product">Model 204</var>.
 
The <var class="product">Fast/Unload</var> manual has not yet been converted; it still is maintained in [http://www.sirius-software.com/maint/download/funr.pdf PDF format].

Latest revision as of 18:05, 16 March 2015