Modifying Keys and Indexes
The automatic creation of primary and foreign keys, and of indexes on these keys, is indicated in the synchronization configuration.
When these creations are requested:
• The primary keys use the columns corresponding to the identifiers.
• The foreign keys use the columns that are included in the tables because of a constraint association.
An index is created for each key.
It is possible to add to, modify, or delete the keys and indexes proposed during generation. To do this:
1. Open the table Properties.
2. Click the Characteristics page.
3. Display the Keys and Indexes sections which can be hidden by default.
The page presents the Keys and Index of the table.
The following is specified in the Keys section:
• The type of key (Key-Type): Foreign or Primary.
• In the case of a foreign key:
• The table referenced.
• Management of repository integrity on update (On Update) and on deletion (On Delete);consult the target DBMS documentation for the order types managed.
When a “migratory” column is created in a table to reflect a constraint association, you can instruct the DBMS to verify the updated value in this column. The DBMS then verifies that this value still exists in the original table (database integrity).When an update (On Update) or delete (On Delete) command is applied to the original table, the DBMS may:
• Update the values in the tables concerned, with the Cascade option.
• Do nothing, with the NoAction option.
• Prohibit updates or deletes, with the Restrict option.
• Reset to the default value in the tables concerned, with the Set Default option.
• Set the value to Null in the tables concerned, with the Set Null option.
The following is specified in the Index section:
• Its Type: Bitmap, Standard, Unique, Unique where not null.
• Its Sort Order (Ascending or Descending).
• If a grouped index Clustered.
Creation of a column from a key or index is not possible. A column must first be created in the table, then connected to the key or index.