Working with indexes
You can create as many single- or multi-valued indexes for a
database table as you need, and you can drop indexes that are no longer
needed.
Update limitation
You can update a table in a DataWindow object only if it has a
unique index or primary key.
Creating an index
In SQL Anywhere databases
In SQL Anywhere databases, you should not define an index on a
column that is defined as a foreign key, because foreign keys are
already optimized for quick reference.
To create an index:
-
Do one of the following:
-
Highlight the table for which you want to create an index
and click the Create Index drop-down toolbar button in
PainterBar1. -
Select Object>Insert>Index from the main menu or
New>Index from the pop-up menu. -
Expand the table’s tree view, right-click on Indexes, and
select New Index from the pop-up menu.
The Index’s properties display in the Object Details
view. -
-
Enter a name for the index in the Index box.
-
Select whether or not to allow duplicate values for the
index. -
Specify any other information required for your
database.For example, in Adaptive Server Enterprise specify whether the
index is clustered, and in SQL Anywhere specify the order of the
index. -
Click the names of the columns that make up the index.
-
Select Save Changes from the pop-up menu.
-
Right-click on the Object Details view and select Save Changes
from the pop-up menu.Any changes you made in the view are immediately saved to the
table definition.
Modifying an index
You can modify an index.
To modify an index:
-
Do one of the following:
-
Highlight the index listed in the table’s expanded tree
view and click the Properties button. -
Select Properties from the Object or pop-up menu.
-
-
Drag the index icon and drop it in the Object Details
view. -
In the Object Details view, select or deselect columns as
needed. -
Right-click on the Object Details view and select Save Changes
from the pop-up menu.Any changes you made in the view are immediately saved to the
table definition.
Dropping an index
Dropping an index removes it from the database.
To drop an index from a table:
-
In the Database painter workspace, display the pop-up menu for
the index you want to drop. -
Select Drop Index and click Yes.