Why joiner is not used after Sequence generator or

问题:

Can any one please explain Why joiner is not used after Sequence generator or Update statergy?

回答1:

It's because joiner may render useless the logic achieved until those two transformation.

Joiner after sequence generator - Purpose of a sequence generator is to generate a new or missing key value. Depending on the join type, you may drop this key value.

Joiner after update strategy - Purpose of update strategy is to determine how a record needs to be processed into the database - insert/update/delete. This decision generally gets made when all the data has been pulled in and every logic/transformation has been applied. Depending on the join type you might miss essential changes to your database.