TD员工入职技术培训之Teradata加载卸载工具V1资料.ppt

议题 议题 议题 议题 议题 议题 TPump Allows near real-time updates from transactional systems into the warehouse. Performs INSERT, UPDATE, and DELETE operations, or a combination, from the same source. Up to 128 DML statements can be included for one IMPORT task. Alternative to MultiLoad for low-volume batch maintenance of large tables. Allows target tables to: Have secondary indexes, join indexes, hash indexes, and Referential Integrity. Be MULTISET or SET. Be populated or empty. Tables can have triggers - invoked as necessary Allows conditional processing (via APPLY in the .IMPORT statement). Supports automatic restarts; uses Support Environment. No session limit — use as many sessions as necessary. No limit to the number of concurrent instances. Uses row-hash locks, allowing concurrent updates on the same table. Can always be stopped and locks dropped with no ill effect. Designed for highest possible throughput. User can specify how many updates occur minute by minute; can be changed as the job runs. TPump Limitations Use of SELECT is not allowed. Concatenation of data files is not supported. Exponential operators are not allowed. Aggregate operators are not allowed. Arithmetic functions are not supported. There is a limit of four IMPORT commands within a single TPump load task. In using TPump with dates before 1900 or after 1999, the year portion of the date must be represented by four numerals (yyyy). The default of two numerals (yy) to represent the year is interpreted to be the 20th century. The correct date format must be specified at the time of table creation. .BEGIN LOAD Statement Many of the .BEGIN parameters are comparable to those for MultiLoad. .BEGIN LOAD SESSIONS max [min] (required) ERRORTABLE tablename (defaults to jobname_ET) ERRLIMIT errcount [errpercent] CHECKPOINT frequency (default is 15 minutes) TENACITY hours (default is 4) SLEEP minutes (default is 6) However, TPump has numerous parameters on the .BEGIN LOAD statement that are unique to