NonStop Systems Introduction

The Relational Database Management System
NonStop Systems Introduction—527825-001
4-13
Data Distribution
The database shown in this figure illustrates the following features of SQL/MX
partitioned tables:
•
Local users can add, change, or delete data in any local partition of the database.
For example, the user on the system A node could change the address of
customer 100 or customer 2600.
•
Local users can add, change, or delete data on any remote partition of the
database. For example, the user on the system A node could delete the row for
customer 6000 on the system B node or add a new row for new customer 9999 on
the system C node.
•
If some partitions of a partitioned table are unavailable because the nodes
containing those partitions are temporarily inaccessible, the local user can still work
with the data in the local partition. For example, the user on the system A node can
still access the rows for customers 1-5000 even if communications line problems
make rows 5001-7500 and 7501-10000 unavailable.
Figure 4-7. SQL/MX Distributed Database
NonStop server C
NonStop server A
Customer
numbers:
1-2500
2501-5000
NonStop server B
Customer
numbers:
5001-7500
Customer
numbers:
7501-10000
VST051.vsd