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<h1 class="topictitle1">Control when access paths are rebuilt</h1>
<div><p>If the system ends abnormally, during the next initial program
load (IPL), the system automatically lists those files that require
access path recovery. You can control when access paths are rebuilt.</p>
<p>You can decide whether to rebuild the access path:</p>
<div class="p"> <ul><li>During the IPL</li>
<li>After the IPL</li>
<li>When you first use the file. </li>
</ul>
</div>
<div class="p">You can also: <ul><li>Change the scheduling order in which the access paths are rebuilt</li>
<li>Hold rebuilding of an access path indefinitely</li>
<li>Continue the IPL process while access paths with a sequence value that
is less than or equal to the <em>*IPL threshold</em> value are rebuilding.</li>
<li>Control the rebuilding of access paths after the system has completed
the IPL process by using the Edit Rebuild of Access Paths (EDTRBDAP) command.</li>
</ul>
</div>
<p>The IPL threshold value determines which access paths to rebuild during
the IPL. All access paths with a sequence value that is less than or equal
to the IPL threshold value rebuild during the IPL. Changing the IPL threshold
value to 99 means that all access paths with a sequence value of 1 through
99 rebuild during the IPL. Changing the IPL threshold value to 0 means that
no access paths rebuild until after the system completes its IPL, except those
access paths that were being journaled and those access paths for system files.</p>
<p>The access path recovery value for a file is determined by the value you
specified for the RECOVER parameter on the create and change file commands.
The default recovery value for *IPL (rebuild during IPL) is 25 and the default
value for AFTIPL (rebuild after IPL) is 75; therefore, RECOVER(*IPL) will
show as 25. The initial IPL threshold value is 50; this allows the parameters
to affect when the access path is rebuilt. You can override this value on
the Edit Rebuild of Access Paths display.</p>
<p>If a file is not needed immediately after IPL time, specify that the file
can be rebuilt at a later time. This should reduce the number of access paths
that need to be rebuilt at IPL, allowing the system to complete its IPL much
faster.</p>
<p>For example, you can specify that all files that must have their access
paths rebuilt should rebuild the access paths when the file is first used.
In this case, no access paths are rebuilt at IPL. You can control the order
in which the access paths are rebuilt by running only those programs that
use the files you want to rebuild first. This method shortens the IPL time
and can make the first of several applications available faster. However,
the overall time to rebuild access paths probably is longer. (Other work might
be running when the access paths are being rebuilt, and there might be less
main storage available to rebuild the access paths).</p>
</div>
<div>
<div class="familylinks">
<div class="parentlink"><strong>Parent topic:</strong> <a href="rbaforzahfpro.htm" title="Rebuilding a database access path might take as much as one minute for every 10 000 records. But some factors might affect the time estimate for rebuilding access paths.">Rebuild access paths</a></div>
</div>
<div class="relref"><strong>Related reference</strong><br />
<div><a href="../cl/edtrbdap.htm">Edit Rebuild of Access Paths (EDTRBDAP) command</a></div>
</div>
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