Export

Enhanced Definition

In the mainframe and z/OS context, "export" refers to the process of extracting data from a z/OS system or its components (e.g., DB2, IMS, VSAM, sequential files) and transferring it to another system, platform, or environment, often in a different format or character encoding. It is a critical operation for data sharing, migration, reporting, and integration with distributed or cloud-based applications.

Key Characteristics

- Data Source Diversity: Data can be exported from various z/OS data sources, including sequential files, PDS/PDSE members, VSAM datasets, DB2 tables, IMS databases, and SMF records.
- Transformation and Formatting: Export processes often involve transforming data from its native mainframe format (e.g., EBCDIC, packed decimal) into a format suitable for the target system (e.g., ASCII, CSV, XML, JSON, fixed-length records).
- Tooling: Common tools for export include DB2 UNLOAD utility, DFSORT (for sorting and reformatting sequential data), custom COBOL or PL/I programs, DFSMSdss (for dataset copying), and file transfer protocols like FTP or SFTP.
- Character Set Conversion: A fundamental aspect is the conversion of character data from EBCDIC (Extended Binary Coded Decimal Interchange Code), native to z/OS, to ASCII (American Standard Code for Information Interchange) or UTF-8 for non-mainframe systems.
- Security and Integrity: Export operations require robust security measures to protect sensitive data during extraction and transfer, along with mechanisms to ensure data integrity and completeness.

Use Cases

- Data Migration: Exporting legacy data from mainframe databases or files to new distributed databases or cloud platforms as part of a modernization effort.
- Business Intelligence and Analytics: Extracting operational data from z/OS systems to populate data warehouses or data lakes on distributed platforms for advanced analytics and reporting.
- Application Integration: Providing data feeds to external applications running on non-mainframe systems, such as customer relationship management (CRM) or enterprise resource planning (ERP) systems.
- Archiving and Compliance: Moving historical data off active mainframe storage to cheaper, long-term archives, often on distributed storage, while maintaining compliance requirements.
- Test Data Provisioning: Creating subsets of production data on the mainframe, exporting them, and loading them into non-mainframe test environments for application development and testing.

Related Concepts

Export is often the "Extract" phase in an ETL (Extract, Transform, Load) process, where data is pulled from the mainframe, potentially transformed, and then loaded into a target system. It is the inverse operation of Import, which involves bringing data *into* the z/OS environment. File Transfer Protocols like FTP and SFTP are the primary mechanisms for physically moving exported data across networks. Data Security and Data Governance policies heavily influence how data can be exported, who can access it, and how it must be protected during transit and at rest.

Best Practices:

Utilize Native Utilities: Whenever possible, use native mainframe utilities like DB2 UNLOAD, IMS UNLOAD, or DFSORT for efficient and reliable data extraction, as they are optimized for z/OS performance.
Plan for Character Set Conversion: Explicitly define and manage EBCDIC to ASCII or UTF-8 conversion rules to prevent data corruption or misinterpretation on the target system.
Implement Robust Security: Encrypt sensitive data during transfer using secure protocols (SFTP, FTPS) and ensure proper access controls are in place for both the source data and the exported files.
Validate Exported Data: Always implement a validation step to compare record counts, checksums, or sample data between the source and the exported files to ensure data integrity and completeness.
Automate and Document: Automate export processes using JCL and scripting, and thoroughly document the data format, transformation rules, and target system requirements for future maintenance and auditing.