# Schema Instance Page

This page shows the content of a schema instance. A name of the schema instance, a repository which the instance belongs to, a native schema name and validation information are given in the upper part of page. There are three sub tabs: Extents, Associated model and Mapping. The Extents and Mapping tabs are the same as in a model page, but data are taken from associated models of this schema instance.

## Extents

The content of all associated models together are shown here. You can filter the table by using appropriate radio button in the filtering line on the top section of the Extents tab. 'Populated' will show all entity data types which have more than zero entity data type values (column '#values'). 'All folders' will show all entity data types. And 'Exact folders' filter shows entity data types which have an instance (column '#instances').

### Table

The table have four columns: Name, Schema, # values and # instances. Name column contains names of entity data types (name of entity definition). Schema column contains schema name of the entity data type. # values column shows an amount of the entity data type values. # instances shows an amount of the instances of this entity data type. The empty cell instead of number in the # values column declares that such entity data type value can not exist (entity data type is a complex). The empty cell instead of number in the # instances column declares that such instance can not exist (entity data type is abstract).
The total number of entity data types, complex entity data types and instances are represented on the bottom section of the Extent tab.

## Associated Models

Associated models for the schema instance are listed here.

### Table

The table consists of three columns: Repository, Model and Schema. In the Repository column repositories for which models belongs to are listed. In the Model column names of models are listed. In the Schema column - a native schema name of the model.

### Editing Line

There are two combo boxes, associated with the table columns, represented on the bottom section of the Associated models tab. You can select a preferred repository in the first combo box. All models available for the repository appear in the second combobox. Models which already present in the schema instance are marked with '*' symbol. After you choose one of them and press 'Add model' button, the model will be added to this schema instance. If you want to remove a model, you need to select it and press 'Remove model' button.

## Mapping

There are all AIM data in ARM context (All ARM entity data types) listed. If there is no ARM schema for this underlying schema, than 'No mapping data' will appear instead of the table. There are two filtering radio buttons on the top section of the Mapping tab. The first one 'Populated folders' lists ARM entity data types which have any available AIM instance. And the second one 'All folders' lists all available ARM entity data types.

### Table

The table consists of three columns: 'Source (ARM)', 'Target (AIM)' and '#'. The Source (ARM) column represents names of the ARM entity data type. The Target (AIM) column represents names of the AIM entity data type. Note. ARM entity data types can be mapped to several AIM entity data types. So there is a relation 'many to many'. The # column shows count of instances which are available for entity data types of ARM and AIM.