Scope

The test suite has been designed to provide a ``dense'' coverage of a restricted range of queries rather than a ``sparse'' coverage of wide range of queries. Additional queries that cover more types of queries may be added later. This section characterizes the types of queries that are, and are not, covered by the test suite.

Temporal query languages may loosely be categorized as relational or object-oriented. The test suite was designed with only relational temporal query languages in mind that may be perceived as temporal extensions of the SQL query language.

The intention is to provide a foundation for comparing the descriptive and operational characteristics and capabilities of temporal data models and query languages. The test suite is not aimed at performance comparisons. Properly extended with additional relation schemas and a variety of large instances, a performance benchmark may be constructed from the test suite.

A number of restrictions are imposed on which types of queries are intended to be included in the current test suite, including the following.

• Queries are restricted to valid time only. Transaction-time related queries are not explored.

• Schema evolution and versioning are not considered.

• Incompleteness is not considered.

• Recursive queries are not included.

• General temporal reasoning is beyond the scope of this version of the test suite.

• Queries involving aggregation facilities are not considered.

• Only queries are included—insertions, deletions, and updates are not considered.

• Continuous attributes such as time are not included.

• The querying of data valid in the future is not explored.

These advanced aspects are excluded solely for pragmatic reasons, and the exclusion is not meant to imply in any way that the aspects are not important. The restrictions simply represent an attempt to reduce the size of the initial test suite to manageable proportions. Specifically, the next version of the test suite is intended to include queries that involve aggregation.