This guide provides an overview of the Matrix42 data layer.
The data layer consists of such basic components as Data Definition and Configuration Item. This guide explains the key terms and describes how these basic schema components work together, as well as how to access and query the data with ASQL.
Another section explains the mechanism of creating, updating and deleting data structures and data with Schema Scripts during Matrix42 system installation and update.
The data structure or Schema of entities in the system is well defined, fixed and there is a direct relation between the product Schema and the physical layout of the tables in the database. You can change this Schema only by using the Schema dialogs or by using Schema scripts. The Schema of the product itself is protected and cannot be changed, only extended.
Data in the Schema is organized by two different items, Data Definitions (DD) and Configuration Items (CI).
- DDs define basic elements like Attributes containing the data. You can also define Relations between DDs.
- CIs combine different DDs to form complex entities in the System. One DD can be used in different CIs, in this case, you have the same attributes and relations in different CIs. This does not mean that different entities contain the same data, they only share the same Schema. CIs are the main items that are usually presented as one entity in a dialog to the user. CIs are also the only items that can be secured for data access.
DDs are always represented by a table in the database. A CI must not have a table in the database, it might be only present in the metadata of the system.
In early versions of the product, Data Definitions were called classes and Configuration Items were called types. You still find these names in some property names like "class type" or "type table" or in the product API.