Shared sequences are reusable sequences that you can use in multiple Sequence transformations. When you use a shared sequence, the Sequence transformation uses the properties of the shared sequence to generate values. Use a shared sequence when you want to assign numeric values within the same sequence to data in multiple mapping tasks.
Multiple mappings and mapplets can use the same shared sequence. When you run the mapping task, Data Integration reserves a set of values in the sequence so that each mapping task generates unique values.
For example, you want to assign a unique ID to entries in your customer tables. You have two mappings that load customer data to the same target table, and the mappings are scheduled to run at the same time. Use a shared sequence to ensure that you do not get duplicate IDs in the target.
You create shared sequences on the New Assets page. You can create non-shared sequences in a Sequence transformation. For more information about creating non-shared sequences, see Transformations.
You can't use shared sequences in mappings in SQL ELT mode.