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Identifying the CDDS
Carefully examine the way data is used among the different databases in your system to determine your CDDSs. Remember that CDDSs are indivisible and mutually exclusive; you cannot split the information in a CDDS so that it goes to different targets, and you cannot contain the same data in more than one CDDS. If you later decide to divide a CDDS, you must reconfigure Ingres Replicator.
For the definition of a CDDS and examples, see Consistent Distributed Data Set (CDDS).
The CDDS Worksheet is divided into the following sections:
CDDS summary
CDDS diagram
Database information
Propagation paths
The CDDS Worksheet and a sample completed CDDS Worksheet are at the end of this section.
CDDS Summary Information
The CDDS summary information defines the scope of the CDDS and how it handles collisions and errors. The following table describes how to fill in the CDDS summary section of the CDDS Worksheet.
Value
Guidelines
CDDS number
This number is an integer in the range of 0-32,767.
The default number is 0.
CDDS name
This name is for your information only. Maximum length is 32 bytes. The default is Default CDDS.
Major tables
Fill in the names of the tables to be replicated. Use the Table Worksheet for more detail.
Collision mode
The possible values are:
PassiveDetection
ActiveDetection
BenignResolution
PriorityResolution
LastWriteWins
For more information, see Collision Modes.
Error mode
The possible values are:
SkipTransaction
SkipRow
QuietCDDS
QuietDatabase
QuietServer
For more information, see How Errors Are Handled.
CDDS Diagram
Use the CDDS Diagram to create a visual representation of your replication scheme. This overview of your replication scheme gives you an instant understanding of your plan and can expose errors or omissions in your plan.
The CDDS Diagram consists of the following elements:
Shapes (databases)
Label each database with its name, number, and target type.
Arrows (propagation paths)
Draw a line for every path, and an arrow pointing at the target. Read-only targets have only incoming arrows, while full peer targets have incoming and outgoing arrows. Label each arrow with the number of the Replicator Server that is propagating to that target.
Database Information
The database information describes the behavior of the database within the CDDS. The following table describes how to fill in the database information section of the CDDS Worksheet.
Value
Guidelines
Database Number/Name
The database number, vnode, and name from the Database Worksheet.
Target Type
Possible values are:
Full peer
Protected read-only
Unprotected read-only
For a description of each target type, its behavior, and the criteria for its use, see CDDS Target Types.
Server Number
The number of the Replicator Servers assigned to propagate transactions to the database.
For more information, see Replicator Server Assignment.
Propagation Paths
Based on the CDDS diagram, fill in propagation paths. For an explanation and examples of data propagation paths, see Data Propagation Paths in the CDDS.
CDDS Worksheet
Define worksheet entries so that an update that occurs on any of the full peer databases within the CDDS is propagated to all of the other databases that participate in the CDDS. For example, if you have two databases in the CDDS that act as full peers, each of them must be an originator in one propagation path and a target in another propagation path. The following table describes how to fill in the propagation path section of the CDDS Worksheet:
Value
Guidelines
Originator DB
Fill in the number of the database where the transaction originated
Local DB
Fill in the number of the database that propagates the transaction to the target
Target DB
Fill in the number of the database that receives the transaction
Comment
This is for worksheet purposes only
The following forms provide examples of CDDS Worksheets.
 
 
The following figure illustrates a completed CDDS Worksheet.
Last modified date: 06/10/2024