SWITCH STREAM command

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Revision as of 22:24, 13 May 2015 by JAL (talk | contribs) (add example)
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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:
    • Journal stream CCAJRNL or CCAJLOG: the currently active data set is closed and the next data set defined to the stream is opened.
    • 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 CCAJRNL command is issued during CHECKPOINT EXTENDED QUIESCE command 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).

See also