Data Import

Key Characteristics

• • Source Flexibility: Data can originate from various sources, including flat files (sequential, VSAM), database dumps from other systems, or direct feeds from distributed applications via network protocols like FTP or SFTP.
  • Batch-Oriented Processing: Imports are frequently executed as batch jobs using JCL and specialized utilities or custom COBOL programs, especially for large volumes of data.
  • Data Transformation and Validation: Often involves transforming data formats (e.g., EBCDIC to ASCII conversion, reformatting), cleansing, and validating data integrity against business rules before it is loaded into the target mainframe data store.
  • Error Handling and Logging: Robust import processes include mechanisms for detecting and reporting errors (e.g., invalid data types, missing required fields) and logging successful/failed records for auditing and recovery.
  • Performance Considerations: For high-volume imports, performance is critical, often requiring optimized JCL parameters, efficient utility usage, and careful resource management to minimize processing time.
  • Security and Access Control: Access to import utilities, source data, and target data stores is strictly controlled using RACF or similar security managers to prevent unauthorized data manipulation.

Use Cases

• • Initial Database Population: Loading a new DB2 table, IMS database, or VSAM file with baseline data from a legacy system or an initial data dump.
  • External Data Integration: Incorporating daily or weekly transaction data, customer updates, or vendor information received from distributed systems into mainframe applications.
  • Data Migration: Transferring data from an older mainframe application or a different platform (e.g., Unix, Windows) to a new z/OS-based application or database.
  • Test Data Loading: Populating development or test environments with representative data sets for application testing and quality assurance.
  • Application Updates: Applying patches or configuration data that are delivered as external files and need to be loaded into specific mainframe datasets or control files.

Related Concepts