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One of the features of <var class="product">[[Fast/Reorg]]</var> is to allow <var>[[Field attributes#Field attribute descriptions|ORDERED INVISIBLE]]</var> field values to be
preserved over a file reorganization in a generic manner.
That is, once you define and load all of your <var>INVISIBLE</var> fields
as <code>ORDERED INVISIBLE</code> or <code>ORDERED NUMERIC INVISIBLE</code>,
you will never again have to worry
about losing <var>INVISIBLE</var> fields over a reorganization.

In addition to preserving <var>ORDERED INVISIBLE</var> fields over a file reorganization,
<var class="product">Fast/Reorg</var> does some cleanup of the <var>INVISIBLE</var> Ordered Index data.
Specifically, index entries associated with
non-existent records are deleted over the reorganization process.
This is accomplished in two steps:
<ol>
<li><var class="product">Fast/Unload</var> does not unload any index data associated with records
outside the range of record numbers unloaded.
Thus, if an unload is done in two passes, the index data unloaded
in the first pass will contain record numbers in the range of records
unloaded in the first pass.</li>

<li><var class="product">Fast/Reload</var> discards index data associated with deleted records.</li>
</ol>
For example, if you unload record numbers 0 through 1,422,633 in an unload,
the invisible index value associated
with record number 2,422,666 would not be unloaded.
Note that if record 944,433 had been deleted but had
Ordered Index invisible data in Table D, this data would be unloaded by <var>UAI</var>.
When <var>LAI</var> attempts to convert
record number 944,433 to a new record number, it would notice that the record
had not been reloaded (because it had never been unloaded) and hence would discard the
Ordered Index data for that record.
This cleanup of <var>ORDERED INVISIBLE</var> Index data ensures that Table D space is not
wasted by <var>ORDERED INVISIBLE</var> Index data for deleted records.

<blockquote class="note">

Note: If you are using <var>INVISIBLE</var> fields (ordered or non-ordered)
with [[File design#Reuse Record Number (X'04')|Reuse Record Number]] (RRN) files, there is nothing that prevents a deleted record
from being replaced by another record, thus rendering the <var>INVISIBLE</var> index value for that record number erroneously "valid" again.
This is a generic problem with RRN files and <var>INVISIBLE</var> fields,
and it is not exacerbated by the use of <var class="product">Fast/Reorg</var>.

In fact, <var class="product">Fast/Reorg</var> gives you an option to eliminate
the use of RRN files in an application requiring the use of
<var>INVISIBLE</var> fields, and instead to rely on the speed and ease of use of <var class="product">Fast/Reorg</var> to recover record numbers
by means of frequent reorganizations. 

==See also==
{{Template:Fast/Reload topic list}}

[[Category:Fast/Reload]]

Fast/Reload and INVISIBLE fields - Revision history

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