MacKinney Systems, Inc.

Tune VSAM, save disk space.

Listcat Plus

Ad Hoc Report Writer

Q:

Can I create my own customized, ad hoc reports from the VSAM file data that is extracted by Listcat Plus?


A:

Yes, if you purchase the add-on companion to Listcat Plus, Ad Hoc Report Writer.  It can easily  create reports using any of the over 70 VSAM-related fields extracted from the LISTCAT ALL by Listcat Plus.  Any of these fields can be used for selection, sorting and printing.  Multiple AND and OR logic statements can be used to select the files that you want to see.  This can be a big help in identifying VSAM files that need to be reorganized and tuned, based on number of extents, CI or CA splits, percent used, EXCPs, record counts, free space, etc..           

Catalog Search Interface program (LCTPCSI)

Q:

What is the Catalog Search Interface program (LCTPCSI), and how does it's report differ from the "main" Listcat Plus report?


A:

LCTPCSI is a program that uses the z/OS Catalog Search Interface (CSI).  It's report is very similar to the basic Listcat Plus report, except that LCTPCSI does not print tuning messages, and does not have as many print options (sorting, warnings, etc.).  LCTPCSI's advantage is that it is much faster than LSTCAT, and that it can be used for quickly printing just a few data sets rather than processing through an entire catalog.  Generics can be used in the data set names when selecting data sets to print.  

How to tune production VSAM files

Q:

How can Listcat Plus be used to help tune production VSAM files in order for them to operate at their optimum performance?


A:

Listcat Plus prints VSAM tuning messages and suggestions, either as part of the report for all files, or as a separate report that just contains files that have tuning messages.  Some of the key statistics and calculations that are involved include data and index CI and CA size, bufferspace size, EXCP to I-O ratio, and number of index levels.

 

Nearing limit of 16 extents

Q:

What triggers the message:
"Above dataset nearing limit of 16 extents for reuseable files?"
Is it a certain number of extents? Does the user have any control over when it is issued?


A:

VSE restricts reusable files to 16 extents per volume. The message you are receiving is generated for reusable files exceeding 10 extents. This is not currently an option you can set.

When to reorganize production VSAM files

Q:

How can Listcat Plus be used to help determine when production VSAM files need to be reorganized in order to operate at their optimum performance and avoid space problems?


A:

Listcat Plus lists VSAM files in a concise one file per line report that makes it easy to see all of the most important statistics relating to the need for reorganizations.  Files are flagged based upon your defined thresholds.  Some of the more important fields and calculations shown include primary and secondary allocations, number of extents, CI and CA splits and freespace, percent full, and number of unused tracks.