Improving Import Task Performance

When import task performance is poor, this is usually because routines are repeated over and over for each import record. You may be able to improve import performance by separately executing routines that are not record-bound, and by removing routines that are not absolutely necessary.

These routines include:

•Computing values such as totals, which are re-adjusted for each import record but could also be calculated in one go AFTER import.

•Row-bound processing that can be performed IN the database at a later time.

•Creation of unnecessary status files.

•SQL processing that requires missing indexes.

Furthermore, you can deactivate certain constraints and relational checks.

To improve import task performance:

1.	Consider computing values as a separate routine outside the import task, if possible.

Perform the calculation as a separate routine, using a SQL task or corrective constraint.

2.	Consider delaying part of the import task until later. Perform a straight import, marking records as needing to be post-processed.

Perform post-processing as a separate routine on the marked records, using a SQL task or corrective constraint.

3.	If you do not require import status files, disable their creation.

4.	Do NOT attempt to cut down on database SQL processing as this is usually not where the performance bottleneck is.

•However, DO consider if any of these statements are slow because they require indexes that were not created. If so, create additional indexes, for instance, on much-used foreign key values.

•Consider disabling rules.