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 database or data files.
![[Warning]](figures/warning.png) | Warning |
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Remember that you should not use lookup tables in the |
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).
Internal: See Internal Lookup Tables.
Internal lookup tables can be:
Externalized: See Externalizing Internal Lookup Tables.
Exported: See Exporting Internal Lookup Tables.
External (shared): See External (Shared) Lookup Tables.
External (shared) lookup tables can be:
Linked to the graph: See Linking External (Shared) Lookup Tables.
Internalized: See Internalizing External (Shared) Lookup Tables.
Types of Lookup Tables
Simple lookup table: See Simple Lookup Table.
Database lookup table: See Database Lookup Table.
Range lookup table: See Range Lookup Table.
Persistent lookup table: See Persistent Lookup Table.
Aspell lookup table: See Aspell Lookup Table.
Lookup tables can be accessed using CTL functions, see Lookup Table Functions.