ER/Studio - Embarcadero Technologies Product Documentation

USING ER/STUDIO > DEVELOPING THE PHYSICAL MODEL
Definition page/tab
Enter or edit a definition or description for the materialized view. If the target database supports it, ER/Studio
adds this definition as a comment when generating SQL code.
DDL page/tab
Displays the CREATE SUMMARY TABLE AS ... (SELECT ...) statement needed to build the node group.
ER/Studio uses the platform-specific parser of the model’s selected database platform to generate the
materialized query table.
Attachment Bindings tab
Bind an external piece of information, or attachment to the materialized query table. You can also remove an
attachment from an object, override an attachment binding’s default value, or change the position of a bound
attachment. To override the value of the attachment you have moved to the Selected Attachments grid,
double-click the Value field of the target attachment. ER/Studio opens the Value Override Editor or a list
depending on the attachment datatype. Attachments are created in the Attachments folder of the Data Dictionary.
For more information, see Attaching External Documents to the Data Model.
Notes
• The materialized query table is not populated when first created. You must explicitly populate the materialized
query table using the REFRESH TABLE statement for system-maintained materialized query tables or by using
the LOAD utility, INSERT statement or the REFRESH TABLE statement for user-maintained materialized query
tables.
Creating and Editing Materialized Views
The performance of data warehousing and decision support system tools can be significantly increased when
materialized views are used. Materialized views increase the speed of queries that access many records, allowing you
to query terabytes of data in seconds. A materialized view is a pre-computed table comprising aggregated or joined
data from fact and possibly dimension tables which is also known as a summary or aggregate table. An example of
such a pre-defined query would be the sum of sales by region for a specific period of time. The storage requirements
of the pre-computed summarizations and data joins of a materialized view are small compared to the original source
data. A materialized view creates a real table that can be indexed and analyzed.
The following database platforms support materialized views:
• Oracle 8.x, 9i, 10g, and 11g
NOTE: The Oracle Materialized View Wizard and Oracle Materialized View Editor share the same
options, except for PreSQL & PostSQL, Permissions, and Attachment Bindings options which are
available only in the editor.
Create a Materialized View
1 In the Data Model Explorer, expand the Physical Main Model, right-click the Materialized Views node, and
then click New Materialized View.
2 Complete the Oracle Materialized View Wizard and then click Finish to create the materialized view.
TIP: Once you have created the materialized view, you can edit it by right-clicking the materialized view
you want to change, and then clicking Edit Materialized View.
The following describe options that require additional explanation.
EMBARCADERO TECHNOLOGIES > ER/STUDIO® 8.0.3 USER GUIDE 195