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Chapter 10. Architecture

10.1. Terminology
10.2. Data Management
10.2.1. Cursoring and Batching
10.2.2. Buffer Management
10.2.3. Cleanup
10.3. Query Termination
10.3.1. Canceling Queries
10.3.2. Timeouts
10.4. Processing
10.4.1. Join Algorithms
10.4.2. Sort Based Algorithms

In addition to these main components, the service platform provides a core set of services available to applications built on top of the service platform.  These services are:

The buffer manager manages memory for all result sets used in the query engine. That includes result sets read from a connector binding, result sets used temporarily during processing, and result sets prepared for a user. Each result set is referred to in the buffer manager as a tuple source.

When retrieving batches from the buffer manager, the size of a batch in bytes is estimated and then allocated against the max and session session limits. If a limit is exceeded and memory space cannot be cleared for the batch, then processing can optionally give up its timeslice and try again.