Reconfiguration of the Replicator

To reconfigure Ingres Replicator, you add new databases to the configuration and change the table schema. The procedures are basically the same as those you use to configure Ingres Replicator.

How You Add a Database to the Replicated Configuration

To add a database to an existing replicated configuration, follow these steps.

Visual DBA:

1. Stabilize the replication environment. For more information, see How You Stabilize the Replication System.
2. Create and populate the new database.
3. Access the main database and add the new database, CDDS, and propagation path information.

   Detailed steps for performing these procedures can be found in the following online help topics:

   • Installing Replication Objects
   • Creating a CDDS
   • Adding Replication Databases
   • Choosing Propagation Paths

     For additional information, see the same topics as above in the chapter "Using Visual DBA for Configuration."

4. Move the replication configuration from the main database to the new database using the Propagate dialog. For more information, see the online help topic Propagate dialog.

Command Line and Replicator Manager:

1. Stabilize the replication environment. For more information, see How You Stabilize the Replication System.
2. Create and populate the new database.
3. Access the Replicator Manager from the main database and add the new database, CDDS, and propagation path information.

   For more information, see Database Summary, CDDS Definition Dialog.

4. Move the replication configuration from the main database to the new database with the MoveConfig command.

   For more information, see Move Configuration Data Window.

How You Copy Replicated Tables Between Replicated Databases

Copying a table between replicated databases is done for several reasons. For example, a table already exists in both databases and is being added to the replication scheme, in which case, it is important to synchronize; or a table exists in only one database and the CDDS is being extended to encompass a new or existing database.

Command Line and Replicator Manager:

To copy replicated tables to other replicated databases, follow these steps:

1. Copy the base replicated table to the new database using the copydb command. (Do not copy shadow and archive tables at this time.) For example:

   copydb dbname tablename

2. Execute the copy.out file against the old database and the copy.in command against the new database. For example:

   sql old_dbname < copy.out

   sql new_dbname < copy.in

3. Access Replicator Manager on the old database to register the table in the new database.
4. Select Configuration from the Replicator Manager for the old database.
5. Select MoveConfig from the Configuration menu.
6. Place the cursor on the new database and select ThisDatabase, from the Move Configuration window, .
7. To confirm that the new table was registered correctly, access Replicator Manager on the new database.
8. From the Replicator Manager for the new database, select Configuration.
9. From the Configuration menu, select Tables.
10. From the Table Registration Summary window, place the cursor on the new table and select Edit.Determine the name of the shadow table and, if necessary, the archive table using the SQL Terminal Monitor.

    Note: The archive table is needed if the base table is part of a Full Peer CDDS at the target database.

11. Use the copydb command to copy the shadow and archive tables from the old database.

    For example:

    copydb old_dbname shadow_name [archive_name]

    sql old_dbname < copy.out

12. Edit the copy.in script and remove any create table, modify, and create index statements. Copy the shadow and archive tables into the new database.

    For example:

    sql new_dbname < copy.in

How You Change the Table Schema

It is possible to change the schema of any table in your replication system. Schema changes must be made on every target database where that table exists.

Visual DBA: For step-by-step procedures, see the online help topic Changing the Table Schema.

Command Line and Replicator Manager:

To change the schema of any table in your replication system, follow these steps:

1. Access Replicator Manager against the database containing the table to be changed.
2. Deregister the table from the Table Registration Summary window of the Replicator Manager using the Deregister option. For more information, see Deregister Tables.

   Note: Deregistering the table causes existing data in the shadow and archive tables to be lost because deregister drops them. If large tables are being reconfigured to expand the width of a column, for example, it is recommended that you copy out the shadow and archive tables before deregistering and reload them later.

3. Use one or more alter table statements to effect the schema changes desired. Tables need to have 4 KB or larger page size.
4. In the Replicator Manager, use the Tables option to perform the following registration tasks on the table:
   1. Register the columns.
   2. Create the support objects.

      If required, create the replicated transaction keys (ShadowTableOnly).

      For more information, see Table Registration Summary.

5. Use the MoveConfig option to move the new database information to other affected databases in your replication system.

   For more information, see Move Configuration Data Window.

6. Activate change recording.

   For more information, see Activate Change Recording Window.

After all databases reflect the change in the table schema, the table is ready for replication on your system.

Optimizing Replicator Catalogs and Support Tables

Once the initial configuration has been defined, or following any significant changes, consider optimizing the Ingres Replicator system catalogs.

Visual DBA: You purge records from shadow and archive tables by expanding the Databases branch in the Database Object Manager, expanding the branch of the desired database, and highlighting Replication. Choose the Arcclean command from the Operations menu. For more information, see the online help topic Arcclean Operation dialog.

You modify the replicated system database by expanding the Databases branch in the Database Object Manager, expanding the branch of the desired database, and highlighting Replication. Choose the Repmod command from the Operations menu. For more information, see the online help topic Repmod Operation dialog box.

Command Line: Use the Arcclean command to purge unneeded records from the shadow and archive tables. See the Command Reference Guide for detailed information and procedures.

Use the Repmod command to modify the replicated system database to predetermined storage structures. For more information, see the Command Reference Guide.

Note: Arcclean remodifies the shadow and archive tables that it cleans up.