How BMC AMI Unload works
The BMC AMI Unload product unloads database objects to sequential data sets.
If you want to unload multiple tables you can have multiple UNLOAD statements in one SYSIN job step. This causes BMC AMI Unload to unload the tables in parallel. To unload the tables serially, code one UNLOAD statement per step in a multi-step job.
You can use the DIRECT command option to select one of two execution modes, or specify DIRECT AUTO to let BMC AMI Unload choose between the two modes based on the options that you specify and the object that you are unloading.
The following table presents an overview of these modes and the benefits of each:
Mode type | Description | Benefits |
|---|---|---|
DIRECT YES | BMC AMI Unload reads data directly from the table space data set or image copy data sets to unload the data, using a SELECT-like syntax for data selection. SELECT functionality is a limited subset of the functionality that is normally available in Db2 SQL. | The primary benefit of the DIRECT YES mode is maximum performance when unloading large volumes of data. Additionally, some features are available in DIRECT YES mode that are not available in DIRECT NO mode. |
DIRECT NO | BMC AMI Unload processes the SELECT statement and reads the data using Db2 dynamic SQL. This mode is not a high-performance solution for unloading large volumes of data. | The benefit of the DIRECT NO mode is a full range of Db2 SQL SELECT functionality, including joined tables, subqueries, and so on. This functionality includes many of the features that are available in BMC AMI Unload including the following features:
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