RCVOPT parameter: Difference between revisions

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<dd>All
<dd>All
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<dt>Introduced
<dd><var class="product">Model 204 V6.1</var> or earlier
<dd><var class="product">Model 204 V2.1</var> or earlier
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Revision as of 12:56, 18 May 2017

Recovery options

Summary

Default value
0
Parameter type
System
Where set
On User 0's parameter line
Related products
All
Introduced
Model 204 V2.1 or earlier

Description

Valid settings of RCVOPT are (options can be summed):

Setting Meaning
X'01' Checkpoints are taken.
X'08' Roll forward information is logged into the journal stream.
X'20' Do not flush the dirty pages in a file that does not do pre-imaging (FRCVOPT X'20' set) during a subtransaction checkpoint. This bit has an effect in Model 204 7.6 and later; for V7.5, it requires an appropriate maintenance zap.

One use of this setting is to set FRCVOPT X'20' for a file that holds SirFact dumps, which can get quite large. This bit prevents a large SirFact dump from causing a subtransaction checkpoint to take a very long time. While this might result in a SirFact dump being lost if the system crashes, such a loss is probably not that critical, so its risk is probably well worth the benefit of faster subtransaction checkpoints.