Feeder

Key Characteristics

• • Data Preparation: Often involves selecting, filtering, reformatting, aggregating, or enriching data from various sources like databases or other files.
  • Input/Output Focus: Primarily an I/O-intensive process, reading from one or more sources (e.g., DB2, IMS, VSAM, sequential files) and writing to an output dataset.
  • Batch Orientation: Typically executed as part of a batch job stream, preceding the main processing step, forming a crucial link in a multi-step job.
  • Modularity: Promotes breaking down complex data flows into manageable, independent steps, enhancing maintainability, reusability, and troubleshooting.
  • Intermediate Datasets: Frequently writes its output to temporary or intermediate datasets (e.g., GDG members, SORTWK files, sequential files) that serve as direct input for downstream processes.

Use Cases

• • Report Generation: A COBOL feeder program extracts specific transaction data from a DB2 table, formats it according to report specifications, and writes it to a sequential file, which is then used by a reporting program.
  • Data Synchronization: Consolidating daily updates from multiple operational systems (e.g., CICS transactions, batch updates) into a single, ordered sequential file to be applied to a master file update program.
  • Inter-system Data Transfer: Preparing and formatting data from an IMS database or VSAM file into a standard flat file format for transmission to an external system via FTP or MQ.
  • Data Warehousing ETL: Extracting raw data from z/OS operational systems, performing initial transformations (e.g., data cleansing, aggregation), and staging it for a data warehouse loading utility.

Related Concepts