In IMS DB (Information Management System Database), there are several types of databases that can be created to accommodate different data storage and access requirements. These database types include :
Hierarchical Databases :
* Hierarchical databases are the most common type of IMS DB database. They organize data in a hierarchical structure, with parent segments containing child segments.
* Data in hierarchical databases is accessed through hierarchical paths, navigating from the root segment down to the desired data using parent-child relationships.
Network Databases :
* Network databases, also known as CODASYL-style databases, support a more complex data model than hierarchical databases.
* In network databases, data is organized into sets and records, with each record potentially connected to multiple sets through pointers.
* Network databases allow for more flexible relationships between data elements, enabling complex data structures and data access paths.
Relational Databases :
* IMS DB also supports relational database features through the IMS/ESA (Enterprise Systems Architecture) product known as IMS Option for Database Manager (IMS DB/DC/DC). This product integrates IMS DB with IBM's DB2 relational database management system.
* Relational databases store data in tables with rows and columns, and they support SQL (Structured Query Language) for querying and manipulating data.
* IMS Option for Database Manager allows IMS applications to access and manipulate relational data stored in DB2 databases, providing integration between hierarchical and relational data models.
Shared Databases :
* Shared databases allow multiple IMS systems to share access to a single database, enabling data sharing and collaboration across multiple systems.
* Shared databases can improve resource utilization and reduce data redundancy by centralizing data storage and access.
Fast Path Databases :
* Fast Path databases are optimized for high-speed, high-volume transaction processing applications.
* They use specialized access methods and caching techniques to achieve fast data retrieval and update operations.
* Fast Path databases are suitable for real-time transaction processing applications with stringent performance requirements.
