GUIDELINE
1.0 SUBJECT: VSAM Tuning Utilities
2.0 DISTRIBUTION: All Current Users
3.0 FROM: Jean L. Turner, Director of DISC
4.0 PURPOSE: To provide information relative to the availability and use of utilities for assisting in maintaining and tuning agency VSAM datasets.
5.0 BACKGROUND: A large percentage of agency datasets are VSAM-based (Virtual Storage Access Method). Improperly defined datasets can result in wasted DASD space and elongated I/O times resulting in increased cost to the owning agency and higher demand for limited system resources. A spot check of existing state VSAM datasets has found instances of up to 50% unused (wasted but charged for) space.
5.1 VSAM tuning and configuration can be time consuming and is not well understood by many users. As a result, many VSAM files are not properly defined. This guideline presents two utilities available to users of the DISC system to assist in defining and tuning their VSAM datasets.
5.2 LISTCAT PLUS is a batch program that will produce a simple listing of statistics and tuning advice for selected VSAM files. The most recent release features an Adhoc Report Writer for customizing reports. VSUM is a sophisticated online TSO-based utility providing considerably more detail and can be used to assist in the design of new VSAM files via modeling.
5.3 It is recommended that an agency utilize LISTCAT PLUS on a regular basis to monitor existing files and use VSUM when planning significant new files or when more detail is required.
6.0 PROCEDURE: The following section describes how to access these two utilities.
6.1 LISTCAT PLUS Batch Utility - LISTCAT PLUS will analyze a specified VSAM dataset or a set of datasets from one or more catalogs. All listings will be sorted alphabetically by VSAM cluster name giving cluster, data and index names. The printed information includes current usage and configuration data as well as recommendations for tuning where warranted.
6.1.1 There are several options the user can specify with LISTCAT PLUS, however the sample JCL below will generate output that should be adequate for most users needs. If you care to investigate other options in this product (including the Adhoc Report Writer feature, described in 6.1.2 below), a copy of the LISTCAT PLUS documentation is available in the DISC Multi Resource Library.
//STEP1 EXEC PROC=LISTPLUS,PRINT=sysoutclass
//STEP1.CARD DD *
P0120001500010010054B DY15100Y2N1 <--note 1
Ddatasetname1@ <--note 2
//STEP1.IDCAMSIN DD *
LISTCAT ALL -
CATALOG(catalog.name) <--note 3
/*
//
Note 1 - Processing options - These are the suggested options, see Reference 1 at the end of the report for more information on available options.
Note 2 - Dataset names - Zero or up to 399 file dataset name cards (the sample shows 1 card) can be supplied. If no dataset cards are provided, all VSAM files in the named catalogs (see note 3) are processed. Otherwise, only the files defined by the 1 or more dataset name cards will be processed. Each dataset card can name a single specific file or a generic (wildcard) name. The format for a dataset name card is as follows:
Column 1 contains the letter 'D'. Columns 2-45 contain the dataset name (cluster, data, index, AIX, etc.) consisting of 1 to 44 characters followed by '@'. The '@' must follow the dataset name whether a single name or a generic list is required.
Examples:
Ex.1 - DTEST.DATA.VSAM@ would only list information for the file TEST.DATA.VSAM
Ex.2 - DTEST.@ would list information for all datasets with the high level qualifier of TEST
Note 3 - One or more catalog cards are required to specify the catalog or catalogs containing your requested VSAM datasets (one catalog per card). A general guide to the various catalogs is shown below, or, you may use option 3.4 in TSO to view dataset/catalog names as CATALOG.*.
CATALOG.DA
CATALOG.DT
CATALOG.RV
CATALOG.SR
CATALOG.SW
CATALOG.USER (for other agencies)
6.1.2 With Release 6.8 of this product, a new feature known as the Adhoc Report Writer was added as an option. A simple set of selection keywords allow the user to design their own report, select files when only certain conditions exist, tailor the sort order, subtotals, etc. This feature becomes very useful when desiring to report on (only) "trouble" datasets (i.e. datasets with control area splits greater than 10, datasets into multiple extents, etc.). For information on how to use this feature, contact the DISC Librarian for a copy of the current LISTCAT PLUS and LISTCAT ADHOC REPORT WRITER User Manual. These manuals will be available for checkout to make your own copy of the manual.
6.1.2.1 A procedure is available for use that contains the necessary JCL for creation of an adhoc report. Overrides are necessary for indicated SYSIN-type statements. Examples are contained within comment sections. The procedureis:
LSTPLSRW
6.2 VSUM On-line Utility - VSUM is invoked as an option within the TSO ISPF menu. The facility contains its own interactive HELP and tutorial. There is also a user manual available through DISC Technical Support. It is recommended that you contact Technical Support if you are interested in investigating this utility. Technical Support will assist you in getting started.
7.0 CANCELLATION: This Guideline cancels Guideline 4603.00 dated 6/1/91. Revisions are indicated with a vertical bar to the left of the hardcopy document.
8.0 CONTACT PERSON: Boyce McCarter - System Software Manager, 785-296-3343