DRDA

Distributed Relational Database Architecture

Enhanced Definition

A protocol enabling database communication between different platforms and DBMS products, allowing distributed DB2 access and remote SQL execution across heterogeneous systems.

Key Characteristics

- Platform-independent database access
- Two-phase commit support
- Location transparency for applications
- Security and authentication integration
- SQL statement forwarding
DRDA Components:
- Application Requester (AR): Client requesting data
- Application Server (AS): Server processing requests
- Database Server (DS): Physical database location
- Communication Manager: Network protocol handling
DRDA Protocols:
- DRDA Level 1: Remote unit of work
- DRDA Level 2: Distributed unit of work
- DRDA Level 3: Distributed request
Supported Operations:
- Remote SQL query execution
- Distributed transaction coordination
- Result set retrieval
- Stored procedure invocation
- Large object (LOB) handling
Connection Types:
- Private connections (exclusive use)
- Shared connections (pooled)
- Persistent connections
- On-demand connections

Use Cases

- Accessing mainframe DB2 from distributed applications
- Consolidating data from multiple platforms
- Enabling three-tier application architectures
- Supporting web service backends
- Database federation and virtualization