Chapter 34. Lookup Tables

Lookup tables are data structures that allow fast access to data stored using a known key or SQL query. This way you can reduce the need to browse a database or data files.

[Warning]Warning

Remember that you should not use lookup tables in the init(), preExecute() or postExecute() functions of the CTL template and the same methods of Java interfaces.

All data records stored in any lookup table are kept in files, in databases or cached in memory.

Lookup tables can be internal or external (shared).

Types of Lookup Tables
Simple Lookup Table
Database Lookup Table
Range Lookup Table
Persistent Lookup Table
Aspell Lookup Table

Lookup tables can be accessed using CTL functions, see Lookup Table Functions.