ForwardonlyCursoren

ForwardonlyCursoren is a term used in data processing to denote a cursor that iterates through a result set strictly in the forward direction. It is typically read-only and does not support moving backward or random access. The exact capabilities depend on the data access API, but a forward-only cursor generally yields one row at a time as it is retrieved from the data source.

Characteristics of a ForwardonlyCursoren include unidirectional movement, a read-only interface, and a tendency to stream rather than preload the entire result set into memory. Because rows are consumed in sequence, revisiting earlier rows is not possible, and certain navigation operations or updates through the cursor are usually not available. This model can reduce memory usage and increase throughput for large datasets, as it minimizes buffering and keeps the cursor state lightweight.

Common use cases for a forward-only cursor are processing large result sets in ETL workflows, streaming data pipelines, logging or audit processing, and any scenario where the consumer only needs to process each row once in order. The pattern emphasizes sequential processing, with a typical flow of opening the cursor, fetching the next row, processing, and finally closing the cursor.

Implementation notes vary by platform. In JDBC, a ResultSet may be created with TYPE_FORWARD_ONLY to indicate forward-only iteration; similar forward-only modes exist in other database APIs and drivers. Limitations include the inability to reposition, to perform random access, or to easily obtain total row counts without executing a separate count query. ForwardonlyCursoren is often contrasted with scrollable or bidirectional cursors that support moving backward and random access.