Oracle7 Server Administrator's Guide

Considerations Before Creating a Database

This section includes the following topics:

Creation Prerequisites

Using an Initial Database

Migrating an Older Version of the Database

Database creation prepares several operating system files so they can work together as an Oracle7 database. You need only create a database once, regardless of how many datafiles it has or how many instances access it. Creating a database can also erase information in an existing database and create a new database with the same name and physical structure.

Creating a database includes the following operations:

creating new datafiles or erasing data that existed in previous datafiles

creating structures that Oracle7 requires to access and use the database (the data dictionary)

creating and initializing the control files and redo log files for the database

Consider the following issues before you create a database:

Plan your database tables and indexes, and estimate how much space they will require.

For information about tables, indexes, and space management, see Chapters 9 through 16.

Plan how to protect your new database, including the configuration of its online and archived redo log (and how much space it will require), and a backup strategy.

For information about the online and archive redo logs, see Chapters 5 and 22 respectively.

For information about database backup and recovery, see Chapters 23 and 24.

Select the database character set. You must specify the database character set when you create the database. If you create the database with the wrong character set by mistake, you can update the SYS.PROPS$ table with the new character set; however, you cannot change characters already there. All character data, including data in the data dictionary, is stored in the database character set. If users access the database using a different character set, the database character set should be the same as, or a superset of, all character sets they use.

Also become familiar with the principles and options of starting up and shutting down an instance, mounting and opening a database, and using parameter files. For information about starting up and shutting down, see Chapter 3.

See Also: "National Language Support" in the Oracle7 Server Reference.

Creation Prerequisites

To create a new database, you must have the following:

the operating system privileges associated with a fully operational database administrator

sufficient memory to start the Oracle7 instance

sufficient disk storage space for the planned database on the computer that executes Oracle7

Using an Initial Database

Depending on your operating system, a database might have been created automatically as part of the installation procedure for Oracle7. You can use this initial database and customize it to meet your information management requirements, or discard it and create one or more new databases to replace it.

Migrating an Older Version of the Database

If you are using a previous release of Oracle7, database creation is required only if you want an entirely new database. Otherwise, you can migrate your existing Oracle7 databases managed by a previous version of Oracle7 and use them with the new version of the Oracle7 software.

See Also: Oracle7 Server Migration manual for information about migrating an existing database.

For information about migrating to Trusted Oracle7, see the Trusted Oracle7 Server Administrator's Guide.

For more information about migrating an existing database, see your operating system-specific Oracle documentation.