Constraints
and Indexes
This
interface allows the creation of special kinds of attributes called constraints.
The constraints are specific types of attributes
that can be defined by one or more attributes of a data set. Usually it
is used to uniquely identify an entry in a table. These constraints can
also be used as indexes.
There are three different types of constraints:
- Primary Key: uniquely
identify an entry in a table, null values are not alloed and each table
can have only one primary key.
- Unique Key: uniquely
identify an entry in a table, null values are allowed and each table
can have multiple unique keys.
- Index: used to optimize
the searching of the data. The attributes used to index the data
will vary depending on the type of index to be created. Supported types
of index are:
Creating Primary or unique keys
- Type - Select the type to be created
(primary key or unique key).
- Name - Define the constraint name.
- Available Properties x Selected Properties -
Select from available properties list which ones will compose the
constraint
and click on icon arrow to transfer them to the selected properties
list. Use the arrows to move from one list to the other as necessary.
- Press Ok to create the constraint or Cancel to close the dialog.
Creating Indexes
- Type - Select the constraint type as Index.
- Name - Define the index name.
- Type - Select the index type (BTree, RTree, QuadTree, Hash).
- Available Properties x Selected Properties -
Select from available properties list which ones will compose the index
and use the arrow icon to transfer them to the selected properties
list. Use the arrows to move from one list to the other as necessary.
- Press Ok to create the constraint or Cancel to close the dialog.