SQL/MX 3.1 Installation and Management Guide (H06.23+, J06.12+)

Understanding and Planning SQL/MX Tables

HP NonStop SQL/MX Release 3.1 Installation and Management Guide—663852-001

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Avoid Renaming Nodes

After an SQL/MX database node has been installed and initialized, do not attempt to

change the node name. The node name is recorded in system metadata entries and

file labels throughout the database. The node number is not recorded anywhere.

Avoid Changing Object Names or Moving Database Objects

You should develop and implement an object-naming strategy that prohibits changing

object names or moving named objects. This strategy is important because many

production databases contain hundreds or thousands of database objects and

hundreds of programs or MXCI scripts that reference the original object names. No

automated tools exist to perform programmatic updates.

The best way to avoid changing object names is to carefully plan for and develop in

advance object names that can be retained over the years and to enforce a policy

against changing names. To help in this endeavor, do not name objects with company,

project, product, or employee names that might need to be changed for legal reasons.

Starting with the SQL/MX Release 3.1, a new feature is introduced to modify the ANSI

and Guardian names of some objects. For more information on this feature, see the

SQL/MX Reference Manual.

Understand the Schema Ownership Rule

Starting with the SQL/MX Release 3.1, new security features are introduced. For more

information on these features, see the SQL/MX Reference Manual.

Avoid Putting Same-Named Catalogs on Multiple Distributed

Nodes

If you create catalogs with the same name on two or more nodes, each node can

access only the objects in the local catalog. You cannot join the tables or indexes in the

same-named catalogs on different nodes.

Understanding SQL/MX Table and File

Structures

A relational database consists of two structural levels, the logical and the physical:



The logical level includes the tables and views you access directly through SQL

statements. When you request an operation on the database or a display of its

contents, you work with the database at the logical level.



The physical level underlies the logical level and is composed of physical files on

disks.