Overview 5
Copyright © 2003, Nortel Networks MCP Database Module Basics
Nortel Networks Confidential
For information about the communication protocols and interactions
between the Database Module and network components, see Figure 2,
“SQL over JDBC,” on page 11.
Each database includes replicated objects and non-replicated objects.
Tables are the only objects that are replicated. Non-replicated objects
include stored procedures, functions, and views.
Minimal, redundant, and variable server configurations are supported in
enterprise deployments. Redundant and variable configurations have
replicated databases. Minimal configurations have a single database.
Data replication
During normal operation, applications send data to the primary
database, which is then stored in tables. The Oracle Server uses a
process called master-master data replication to constantly transfer
changed data from the primary database to the secondary database.
See “Data transfer” on page 7.
Consequently, in the unlikely event of failure of the primary database,
the secondary database should always contain a copy of the data. See
“Fault management” on page 8.
For applications, the secondary database operates in limited write
mode only, which means that it is read only except for registrations. See
Table 1, “Database operational states,” on page 6 and “Fault
management” on page 17.
The Database Module replication environment has the states of
operation identified in Table 1, “Database operational states,” on
page 6. The primary database ordinarily operates in the normal state,
ATTENTION
Database Module deployment creates or updates both replicated
objects (database tables) and non-replicated objects (stored
procedures, functions, and views) on both databases.