Within a single invocation of Teradata TPump, one or more distinct Teradata TPump tasks can be executed in series with any Teradata TPump support commands.
The Teradata TPump task provides the acquisition of data from client files for application to target tables through INSERT, UPDATE, or DELETE statements that specify the full primary index. Data is retrieved from the client, and sent as transaction rows to the database, which are immediately applied to the various target tables.
Each Teradata TPump task can acquire data from one or many client files with similar or different layouts. From each source record, one or more INSERT, UPDATE, or DELETE statements can be generated and directed to any target table.
- The language of Teradata TPump commands and statements is used to describe the task which needs to be accomplished.
- Teradata TPump examines all commands and statements for a task, from the BEGIN LOAD command through the END LOAD command, before actually executing the task.
- After all commands and statements involved in a given task have been processed and validated by Teradata TPump, the Teradata TPump task is executed as described in this and subsequent sections.
- Optionally, Teradata TPump supports data serialization for a given row, which guarantees that if a row insert is immediately followed by a row update, the insert is processed first. This is done by hashing records to a given session.
- Teradata TPump supports bulletproof restartability using time-based checkpoints. Using frequent checkpoints provides a greater ease in restarting, but at the expense of the checkpointing overhead.
- Teradata TPump supports upsert logic similar to MultiLoad.
- Teradata TPump supports insert/update/delete statements in multiple-record requests.
- Teradata TPump uses macros to minimize network overhead. Before Teradata TPump begins a load, it sends the statements to the database to create equivalent macros for every insert/update/delete statement used in the job script. The execute macro requests, rather than lengthy text requests, are then executed iteratively during a job run.
- Teradata TPump supports interpretive, record manipulating and restarting features similar to MultiLoad.
- Teradata TPump supports conditional apply logic, similar to MultiLoad.
- Teradata TPump supports error treatment options, similar to MultiLoad.
- Teradata TPump runs as a single process.
- Teradata TPump supports Vantage internationalization features such as kanji character sets.
- Up to 1500 operations can be packed into a single request for network efficiency. The limit of 1500 may vary as the overall limit for a request is one megabyte. Teradata TPump assumes that every statement is a one- or two- (for fallback) step request.