Resolving MLOAD error 2571
MLOAD works in five phases, unlike FastLoad, which only works in two phases. MLOAD can fail in either phase three or four. Figure shows 5 stages of MLOAD.
Preliminary: Basic setup. Syntax checking, establishing session with the Teradata Database, creation of error tables (two error tables per target table), and the creation of work tables and log tables are done in this phase.
- DML Transaction phase: Request is parse through PE and a step plan is generated. Steps and DML are then sent to AMP and stored in appropriate work tables for each target table. Input data sent will be stored in these work tables, which will be applied to the target table later on.
- Acquisition phase: Unsorted data is sent to AMP in blocks of 64K. Rows are hashed by PI and sent to appropriate AMPs. Utility places locks on target tables in preparation for the application phase to apply rows in target tables.
- Application phase: Changes are applied to target tables and NUSI subtables. Lock on table...
