Add database partitions to the relational source to increase the speed of the Data Integration Service query that reads the source. If the source does not have database partitions, the Data Integration Service uses one thread to read from the source.

Relational databases might have options that enable parallel queries to the database. Refer to the database documentation for these options. If these options are not enabled, the Data Integration Service runs multiple partition SELECT statements serially.

Each database provides an option to separate the data into different tablespaces. Each tablespace can refer to a unique file system, which prevents any I/O contention across partitions.

The Data Integration Service creates a separate connection to the source database for each partition. Increase the maximum number of allowed sessions so that the database can handle a larger number of concurrent connections.