VCA EXTENTDETAIL Statement
The EXTENTDETAIL statement has two operands:
micsrm140
EXTENTDETAIL fff record
The EXTENTDETAIL statement has two operands:
- fff is optional and is a file identifier. Valid values are DAA and _VS. If fff is not specified, the value for record applies to both files.
- record is required.
Valid values are:
- YES - record details for extent.
- NO - do not record details for extents.
If EXTENTDETAIL is not coded, the default is as follows:
EXTENTDETAIL DAA NO EXTENTDETAIL _VS NO
VSAM data sets that have more than 16 extents have one or more extra observations in the VCADAA and VCA_VS DETAIL timespans that describe the 17th through 128th extents. Each extra observation describes the next set of 16 extents. The extra observations take DASD space and time to build and are important only if you run the TRACK MAP standard report or do very detailed extent reporting.
To save processing time and DASD space, you can specify that the extra observations are to be deleted during the DAILY DAY090 step. They can be deleted from either or both of the VCADAA and VCA_VS files by coding the EXTENTDETAIL parameter accordingly.
For example, to keep all the details for extents 17 through 128 for VSAM on the VCA_VS file but keep none on the VCADAA file, code two statements as follows:
EXTENTDETAIL _VS YES EXTENTDETAIL DAA NO
To eliminate all recording of extent data beyond 16 extents in both files, code:
EXTENTDETAIL NO
Note:
Saving space in the DETAIL timespan by coding EXTENTDETAIL NO makes the Volume Track Map Report unable to map the physical locations of the entire volume. For an example of this report, see Volume Track Map Report.Because the Track Map Report uses the VCADAA file, you could save some space and still produce the report by coding:
EXTENTDETAIL _VS NO EXTENTDETAIL DAA YES
Certain reports in the
MICS
StorageMate Option look at extent locations of the VTOC and the VVDS and are not affected adversely if you code EXTENTDETAIL NO.