Allocating FSTRACE

You can allocate FSTRACE during your session or in batch. You can store the results in a file or sequential data set.

In this section: Allocate FSTRACE Online Allocate FSTRACE in Batch Free Trace Allocations

The trace facilities are intended for use in query optimization and problem debugging. Application programs should not be written to depend on the format or content of any trace, as they may change in later releases.

How to Allocate FSTRACE Online

You can allocate FSTRACE to an MVS sequential data set or CMS file. To capture trace data in a sequential file, issue the appropriate command from the command level. For example:

{MVS|TSO} ALLOC F(FSTRACE) DA('userid.FSTRACE') SHR REU

or

DYNAM ALLOC DD FSTRACE DATASET userid.FSTRACE SHR REUSE

or:

CMS FILEDEF FSTRACE DISK FSTRACE DATA A

Note: DCB attributes are LRECL=80 and RECFM=F.

To view the trace information, use the system editor or the FOCUS TED editor.

How to Allocate FSTRACE in Batch

You can write trace results to SYSOUT. BLKSIZE information is optional, but should be compatible with other FSTRACE formats. For example, to allocate DDNAME FSTRACE:

//FSTRACE   DD   SYSOUT=*,DCB=(LRECL=80,BLKSIZE=80,RECFM=F)

You can also write trace results to an MVS sequential data set. First, allocate the FSTRACE data set in a prior batch step (as shown) or in ISPF:

//ALLOC    EXEC PGM=IEFBR14
//FSTRACE  DD   DISP=(,CATLG),DSN=userid.FSTRACE,
//         UNIT=SYSDA,VOL=SER=USERM1,SPACE=(TRK,(5,5)),
//         DCB=(LRECL=80,BLKSIZE=80,RECFM=F)
                      .
                      .
                      .

Then, allocate the trace data set with DISP=MOD in the batch FOCUS JCL:

                      .
                      .
                      .
//FOCBATCH EXEC PGM=FOCUS
//FSTRACE  DD   DISP=(MOD,KEEP,KEEP),DSN=userid.FSTRACE

How to Free Trace Allocations

To clear the FSTRACE allocation:

{MVS|TSO} FREE F(FSTRACE)

or

DYNAM FREE FILE FSTRACE

or

CMS FILEDEF FSTRACE CLEAR