[DERBY-6467] Document context-aware table functions.

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 10.11.1.1
• Fix Version/s: 10.11.1.1
• Component/s: Documentation
• Assignee: Camilla Haase
• Reporter: Richard N. Hillegas
• Created: 02/Feb/14 21:52
• Updated: 03/Sep/14 11:53
• Resolved: 20/May/14 13:31

Description

Now that we have added AwareVTI and VTIContext to the public api, it would be good to document how to use them. Perhaps we could add a "Writing a context-aware table function" subtopic under the "Programming Derby-style table functions" topic in the Developer's Guide.

As an example, the new subsection could use ArchiveVTI together with the script which is part of the 2014-02-02 comment on DERBY-6117.

Context-aware table functions are useful when you need to describe a family of results which have the following properties:

1) Each result in the family has a shape which is determined by a different table.

2) There may be several results associated with a given table. In addition to having the same shape, the sub-family of results differ from one another based on some variables which cannot be represented as ? parameters in a SELECT statement.

Issue Links

• relates to: DERBY-6117 Extend the Table Functions java interface to pass more query context information from Derby