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Data Cartridge

References

The Oracle reference for Data Cartridges can be found in the following online links:

Simple Description

A Data Cartridge is a software package that conforms to a set of programming specifications and uses supplied functions. This allows a software developer to extend the functionality of the Oracle database by incorporating extra knowledge into how data is indexed. A Data Cartridge is put forward as a means for Software Development Companies to sell packaged solutions to clients who are also software developers.

Design Patterns Description

For those of you who are into Design Patterns, a Data Cartridge is a Factory that creates a index type which is a Facade. This index type is then instantiated as a Domain Index.

Example of a Data Cartridge Implementation

With each distribution of Oracle Database Server comes an implementation of Data Cartridge which is called Oracle Text. Further references can be found in:

Hierarchy of Types of Indexing

The hierarchy of types of indexing, in order of increasing complexity, is:

No index (data is accessed by table scans)
Simple index (CREATE INDEX a ON table(column))
Functional index (CREATE INDEX a ON table(function(column)))
Domain index (CREATE INDEX a ON table(column) INDEXTYPE IS type)

Both of the last two (2) require extra work to done before the index can be used.

Recommended Approach to Data Cartridges

Are you sure you want to implement Data Cartridges?
Have a good night's sleep (this is your last chance of getting some)
Are you really sure want to do this?
Read the manual.
Implement the sample code.
Are you still sure?
Use the sample code as a basis for a prototype.
Measure the performance on a substantial amount of data.
Curse the day you were born.
Calm down and review the performance hints.
Reconsider your decision
Update this Wiki entry with your tale of woe.
Implement your design

Performance Hints

Avoid correlated function calls
Use out arrays on ODCIIndexFetch calls
Optimise your internal data structures
Instrument your code
Really instrument your code

dfhawthorne	Latest page update: made by dfhawthorne , Nov 16 2007, 4:19 AM EST (about this update About This Update Initial draft - dfhawthorne 364 words added view changes - complete history)
	Keyword tags: Application Programming Data Cartridge Domain Index More Info: links to this page

Threads for this page

	Started By		Thread Subject	Replies	Last Post
	rwhomer		Chemistry Data Cartridges	0	Jan 15 2008, 6:47 PM EST by rwhomer
			Thread started: Jan 15 2008, 6:47 PM EST Watch I have implemented 2 data cartridges and managed the development of a third one. The hard part is if you want to get the Optimizer to make useful choices. With chemistry cartridges at least many queries are highly selective and many more are very very unselective. Communicating this to Oracle isn't all that easy. And forget about using a version earlier than 10g. The 9i version always chose to use the domain index even if there was a much betteer access path. Its an interesting technology though and for some applications its the best way to integrate complex data with Oracle. 1 out of 2 found this valuable. Do you find this valuable? Do you? Keyword tags: Application Programming Data Cartridge Domain Index Post reply