There is a default FILE definition, DFHLRQ, for the local request queue data set in the CICS®-supplied RDO group DFHCBTS. DFHCBTS is included in the default CICS startup group list, DFHLIST. Figure 36 shows the default definition.
DEFINE FILE(DFHLRQ) GROUP(DFHCBTS)
DESCRIPTION(Scheduler Services - Local Request Queue)
RLSACCESS(NO) LSRPOOLID(1)
READINTEG(UNCOMMITTED) DSNSHARING(ACCREQS)
STRINGS(10) STATUS(ENABLED)
OPENTIME(FIRSTREF) DISPOSITION(OLD)
DATABUFFERS(11) INDEXBUFFERS(10)
TABLE(NO) RECORDFORMAT(V)
ADD(YES) BROWSE(YES)
DELETE(YES) READ(YES)
UPDATE(YES) JOURNAL(NO)
JNLREAD(NONE) JNLSYNCREAD(NO)
JNLUPDATE(NONE) JNLADD(NONE)
JNLSYNCWRITE(NONE) RECOVERY(BACKOUTONLY)
FWDRECOVLOG(NO) BACKUPTYPE(STATIC)
For performance reasons, you may want to change the default definition. For example, because the LRQ is frequently accessed it may be sensible to put the file in its own LSR pool, or to define it to use VSAM nonshared resources. This way, BTS operations will not be affected by other file accesses.
If it’s possible that, in your BTS system, many activities may be initiated at the same time (consider a banking application that produces a statement for each customer at the same time each month), it may be a good idea to set the number of strings and buffers to the value of the MXT system initialization parameter. Doing so would avoid string and buffer waits. (You could also use TRANCLASS definitions to further throttle the number of concurrent transaction instances and thus LRQ file accesses.)
To alter the definition of DFHLRQ, you can do either of the following:
If you use this method, you are recommended to take a backup copy of the definition after you have altered it, to prevent your changes being lost if maintenance is applied to the CSD.