SWITCH STREAM command: Difference between revisions
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<td>This optional parameter causes any disabled parallel GDG members to be reopened during the switch. | <td>This optional parameter causes any disabled parallel GDG members to be reopened during the switch. | ||
<p> | <p> | ||
Valid only for a CCAJLOG parallel stream defined with GDG members, as in the following example, which specifies two complete copies of CCAJLOG using GDGs as a base:</p> | Valid only for a <var>CCAJLOG</var> parallel stream defined with GDG members, as in the following example, which specifies two complete copies of CCAJLOG using GDGs as a base:</p> | ||
<p class="code">DEFINE STREAM CCAJLOG … PARALLEL=(P1,P2) … | <p class="code">DEFINE STREAM CCAJLOG … PARALLEL=(P1,P2) … | ||
DEFINE STREAM P1 … GDG=(D1) … | DEFINE STREAM P1 … GDG=(D1) … | ||
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<li>If you specify: | <li>If you specify: | ||
<ul> | <ul> | ||
<li> | <li>A journal stream (<var>CCAJRNL</var> or <var>CCAJLOG</var>): the currently active data set is closed and the next data set defined to the stream is opened. </li> | ||
<li> | <li>A checkpoint stream (<var>CHKPOINT</var> or <var>CHKPNTS</var>): the currently active data set in the stream is closed after the next record is written to the data set.</li> | ||
</ul></li> | </ul></li> | ||
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<ul> | <ul> | ||
<li>[[DEFINE STREAM command]] </li> | <li>[[DEFINE STREAM command]] </li> | ||
<li>[[COPY STREAM command]] </li> | |||
<li>[[Configuring checkpoint and journal data streams]] </li> | <li>[[Configuring checkpoint and journal data streams]] </li> | ||
</ul> | </ul> | ||
Revision as of 22:02, 14 May 2015
Summary
- Privileges
- System manager
- Function
- You can switch streams — parallel, ring, concatenated, GDG — to the next member at any time.
Syntax
SWITCH STREAM streamname [ RESET ]
Where:
| streamname | CCAJRNL, CCAJLOG, CHKPOINT, or CHKPNTS. The command is valid only for these streams. |
|---|---|
| RESET | This optional parameter causes any disabled parallel GDG members to be reopened during the switch.
Valid only for a CCAJLOG parallel stream defined with GDG members, as in the following example, which specifies two complete copies of CCAJLOG using GDGs as a base: DEFINE STREAM CCAJLOG … PARALLEL=(P1,P2) … DEFINE STREAM P1 … GDG=(D1) … DEFINE STREAM P2 … GDG=(D2) … DEFINE DATASET D1…. DEFINE DATASET D2… |
Usage notes
- If you specify:
- A journal stream (CCAJRNL or CCAJLOG): the currently active data set is closed and the next data set defined to the stream is opened.
- A checkpoint stream (CHKPOINT or CHKPNTS): the currently active data set in the stream is closed after the next record is written to the data set.
- If a
SWITCH STREAM CCAJRNLcommand is issued duringCHECKPOINT EXTENDED QUIESCEcommand processing, the journal is switched, a new checkpoint is issued, and the duration of the extended quiesce time-out set in CPQZSECS is reset to its maximum, original value (disregarding the already-elapsed time).