What Does CA IDMS/DB Analyzer Do?

idms
CA IDMS/DB Analyzer is a parameter-driven batch utility that examines the physical structure of a database, creates an iterative statistical data file based on this examination and then produces a series of user-requested analytical reports.
CA IDMS/DB Analyzer examines a database and collects data on important physical characteristics within areas, within record and set types, and within the index or indexes associated with the database.
This data is stored in the statistical data file. Since the statistical file is iterative, storing several generations of historical data, CA IDMS/DB Analyzer can compare current statistics with historical statistics or two different sets of historical statistics with each other. This capability allows you to detect trends in the database over a period of time or to assess the effects of reorganization.
CA IDMS/DB Analyzer creates reports by using information either taken directly from the database or computed from the contents of the statistical file.
Statistic Collection
CA IDMS/DB Analyzer produces statistics that provide a firm foundation for decision making. These statistics show raw counts, percentages, means, minimum and maximum values, and the distribution of values across page ranges and other types of ranges. Statistics are collected at four different levels of physical organization -- AREA, RECORD, SET, and INDEX. These statistics permit:
An analysis by
AREA
and
RECORD
TYPE
of such characteristics as:
  • Total record occurrences
  • Relocated record occurrences
  • Fragmented record occurrences
  • Logically deleted record occurrences
  • Savings due to record compression
  • Space used
An analysis by
AREA
of characteristics such as:
  • Space allocated for pointers, data, line indexes, and headers/footers
  • Free space
  • Physically and logically full pages
  • Space management pages
  • Empty pages
An analysis by
SET
TYPE
of such characteristics as:
  • Owner record occurrences
  • Owner occurrences with one or more members
  • Page distribution of set occurrences
  • Member record occurrences on target page
  • Member record occurrences on overflow
  • Page changes when set walking
An analysis by
INDEX SET
of such characteristics as:
  • Upper level blocks, page spread, and table entries
  • Upper level blocks stored inside and outside bottom level offset
  • Bottom level blocks, page spread, and table entries
  • Number of index levels.
Reporting with Quick Reference Histograms
CA IDMS/DB Analyzer produces four different reports: Area, Record, Set, and SR8 Index -- which include quick reference histograms. CA IDMS/DB Analyzer can also produce a comparative version of each of these four reports.
Area Reports
-- CA IDMS/DB Analyzer can produce an Area Report for every area in your database. This report is composed of four sections. The Area Statistics Section provides you with raw counts and percentages for a comprehensive list of area characteristics. The distribution of certain characteristics over meaningful ranges (page ranges, for example) is shown in the Distribution Section. The Histogram Section displays Distribution Section information in the form of a histogram or bar chart for easy reference.
The Analysis by Record Section provides summary statistics by record type for both active and logically deleted records.
Record Reports
-- A three-section report for each record type in your database can be produced. Statistics for distribution of selected characteristics is shown in the Distribution Section and displayed as a bar chart in the Histogram Section.
Set Reports
-- Statistics for each set type in your database are shown in Set Reports. A Set Report consists of four sections. The Set Statistics Section, Distribution Section, and Histogram Section, which apply to set type characteristics, are similar to those in the Area and Record Reports.
The Multi-Member Set Analysis Section shows an analysis of each record type in a multi-member set.
SR8 Index Reports
-- A three-section SR8 Index Report can be produced for each SR8 index set in your database. Index definition; upper and bottom level statistics; table entry distributions; and histograms are shown in the SR8 Index Report. Integrated index sets (indexed sets) are referred to as SR8 sets in this user section.
Comparative Reports
-- Area, Record, Set, and SR8 Index Reports are each available in a comparative version.
If you want to compare the status of a specific area at two different times, you can produce a Comparative Area Report. Comparative reports draw information from two different statistical files. Old and new values, as well as the variance or difference between them, are shown.
Parameter Statement Syntax Checking
CA IDMS/DB Analyzer is driven by one mandatory and four optional parameter statements. These parameter statements make it easy for you to perform processing that meets your exact needs no matter how general or specific they may be.
In addition, you can check the syntax of all entered parameter statements before processing is begun. This makes it possible for you to run CA IDMS/DB Analyzer over a weekend, or at some other time when you are not present, without the possibility of abnormal termination of a program because of a syntax error. If CA IDMS/DB Analyzer does encounter a syntax error during a processing run, it checks all other parameter statement syntax for correctness before terminating abnormally. Consequently, you can correct
all
syntax errors before requesting another processing run.