SQL/MP Version Management Guide

Database Versions

Compaq NonStop™ SQL/MP Version Management Guide—429833-001

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Catalog Format Version

A catalog format version number is another version number assigned to an SQL user

catalog or an SQL system catalog. The catalog format version of an SQL catalog

corresponds to the oldest version of SQL/MP software that can read from or write to the

catalog. Catalog format versions are intended primarily for internal use by SQL/MP.

A catalog format version number, unlike a catalog version number, is based on the

physical structure of an SQL user or system catalog. Therefore, it changes only when the

structure of a catalog changes. For example, the catalog format version of a catalog

changes when a new table is added, when a new column is added to an existing table, or

when an existing column is modified to accept values it could not accept before.

When a catalog is assigned a new catalog format version number, it is also assigned a

new catalog version number. Because the catalog format version number does not

always change when its corresponding catalog version number changes, the catalog

format version number of a user or system catalog is always equal to or less than its

corresponding catalog version number.

Because the catalog format version of a user or system catalog is based on the physical

structure of the catalog, all catalogs with the same set of catalog tables and the same

collection of column definitions have the same catalog format version number.

For catalogs produced by version 300 and newer SQL/MP software, the catalog version

and the catalog format version are the same. In future versions of SQL/MP software, the

catalog format version of a user or system catalog might be older than the catalog

version, but it can never be newer. This restriction means that the catalog version might

be incremented without a corresponding increase in the catalog format version.

System Catalog Version

The version of the system catalog is treated like the version of any other catalog, with

one exception: The system catalog can register user catalogs with versions newer than

the version of the system catalog. As a result, you can install user catalogs with newer

versions on a system without upgrading to a newer version of the system catalog.

Figure 3-1. Catalog Version and Object Version: Valid Relationships

Version 1

Catalog

Version 315

Catalog

Version 2

Catalog

VST005.vsd

V1 Objects

V2 Objects

V1 Objects

V2 Objects

V300 Objects

V310 Objects