Overview

You can tune the size of collection blocks and the load factor attribute at the collection type or instance level, by using the Tuning sheet on the Define Class dialog for a Collection subclass.

The JADE development environment enables you to tune collection block parameters at the type (collection class) level.

You can specify the collection block size and load factor attributes for a specific instance by using collection runtime instance methods.

The ability to tune the size of blocks is particularly useful in Btree structures, as the block size can determine the number of levels or the height of a Btree required to contain a specific population (number of entries). Minimizing the number of levels in a Btree has been shown to improve the overall performance for typical use cases with large collections.

The load factor attribute enables you to affect the loading of blocks when a Btree block split occurs. The optimal value for this is dependent on the key order in which entries are inserted; for example, purely sequential versus random insertion.

For details about the behavior of collections, see "Collection Behavior", later in this chapter.