ER/Studio - Embarcadero Technologies Product Documentation

USING ER/STUDIO > DEVELOPING THE PHYSICAL MODEL
Removing Unnecessary Tables
Table Merge Denormalization
A table merge denormalization removes unnecessary tables by combining two or more unrelated tables with the same
primary key into a single table containing all tables’ columns.In the following example, all the fields from the jobs table
are merged into the dbo.newjobs table.
To create a new table merge mapping:
1 Display the physical model.
2 Click and drag or CTRL-click to select the tables to be merged.
3 Right-click one of the selected tables and then click Denormalization Mapping > Table Merges.
4 Complete the Table Merge Denormalization Wizard as required.
Notes
• If the Table Merges menu choice is dimmed, check to make sure you have not accidentally selected another table
or some other object.
• The first panel of the wizard is merely informative. If the correct tables are listed, click Next; otherwise, click
Cancel and redo your selection.
Undo a Denormalization Mapping
1 In the Data Model tab of the Data Model Explorer, right-click the mapping (under the Denormalization Mapping
section of the physical model).
2 Select Undo Denormalization Mapping.
before after
NOTE: If the Reflect changes to original tables option was selected for the mapping, any changes made
to the denormalized tables have been propagated to the original tables. Otherwise, undoing the
mapping will restore the original tables in their pre-mapping state.
Synchronizing Physical and Logical Models
After normalizing or denormalizing the model you may want to synchronize it with the real-world database. Using the
Submodel Synchronization Utility, you can see the differences found and decide which changes you want to change.
For more information, see Synchronizing Submodels.
EMBARCADERO TECHNOLOGIES > ER/STUDIO® 8.0.3 USER GUIDE 217