IDMS: The three types of SCHEMA explained

Products

• IDMS

Issue/Introduction

In IDMS, there are three distinct types of SCHEMA.

This article describes the differences.

Environment

Release : All supported releases.
Component : CA IDMS/DB

Resolution

The three different types of IDMS schema can be broadly described as follows:

1. Network-defined
   This is the traditional IDMS network schema which groups the logical AREAs, RECORDs and SETs together together under one entity. SUBSCHEMAs are then generated against a SCHEMA for application programs to reference.
   
   
2. SQL-defined
   This is for SQL-defined databases and is little more than a means of grouping all native SQL-defined database entities together in one collection. This includes tables, views, table procedures and procedures.
   
   
3. SQL schema for network database
   This is essentially an SQL schema, however its only purpose is to point to a combination of network schema and DBNAME, and expose the records in that database as SQL tables, with the SQL schema name assigned.
   This type of schema can be used for nothing else. Views, table procedures and procedures must be defined in a "type 2" schema above, even if they are more related to the network database in question.