Working with Resources

It can be advantageous at times to attach auxiliary information to a particular table that does not conform to the record structure of that table. For example, features such as versioning or special flags relating to the status of the table. Generally, this information is not repeated in every record of the table. You could create a special record, with a special key value, that you do not process as you do your regular records. Ultimately, however, this forces exceptional handling routines for this special case and can impose a heavy maintenance cost on the life cycle of the application.

c-treeACE provides a unique feature created for exactly this purpose. c-treeACE Resources. Resources are special variable-length records stored within your data file, whether you use fixed or variable length records. A set of c-treeACE API functions provide access to create, update and delete these resource records. These records do not require a key in an index, therefore your program does not access them via routine data handling functions.

Resources provide critical support for many advanced c-treeACE features. FairCom defined resources allow seamless functionality of many of the c-tree Plus ODBC Drivers, r-tree Report Engine, Incremental ISAM functionality, conditional index support, c-treeDB and c-treeACE SQL. These resources continue to be important as new technology is added. Resources are added either automatically by some c-treeACE features or manually by the developer. The use of resources requires the RESOURCES define in the c-treeACE library, which is the default.

This section focuses on user defined resources added by you, the developer, and provides important background information on the use of resources.