Mapset Data Model |
It is helpful to understand Chameleon's data model for storing table mappings when designing and working with table grammars. The following diagram shows the relationships between the various objects inside Chameleon:
Mapset Data Model
When you have a table included in the table grammar for a message there are two items being referenced:
- The table itself, and
- The mapset used to define the mappings for the table in this message.
You need to determine whether you want to:
There are many advantages and disadvantages for sharing mapsets across messages, as described in the table below:
| Advantages | Disadvantages | |
|---|---|---|
| Sharing Mapsets | Re-mapping a field for one message updates the mapping for all your other messages. | If the table is mapped to a different set of segments, then using a common mapset will not work. This issue arises because Chameleon uses numerical indexes to store the mappings. So if the same mapset is used for two messages when the segments are different then the mappings will be incorrect for one of the messages. If a table is mapped to the root of the message (or to a group of segments), and the order of the segments changes then the mappings will break. |
One way to avoid these problems is to make your tables quite small and map them to individual segments. This makes it very easy to re-use your mappings. The other way is to make sure you use separate mapsets for each message when a table is used in more than one message.
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Mapsets are created, renamed, selected and deleted via the Mapping Window using the drop-down menu, located in the bottom left corner. | ||
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