Loading and Unloading Databases

This chapter provides information on how to unload and reload a database or selected tables using the unload database and copy database operations of Ingres.

The unload database and copy database operations are most often used to copy or move a database or selected tables from one instance to another. They allow you to copy or move data from one instance to another instance with the same or different hardware or operating system.

You can also use these commands to:

• Copy a database or tables from one database to another on the same instance
• Document your database or specific tables using the "create" scripts produced by these operations
• Make static copies of your database or selected tables for the purpose of recovery
• Archive data that you want to purge from the database or reload later

This chapter also briefly describes the genxml and xmlimport utilities, which can be used to convert Ingres data into XML. XML is a cross-platform, software and hardware independent format for transmitting information across the Internet. The XML data files produced can also be processed by other XML-enabled databases and applications.

Unload and Copy Operations

The unload database and copy database operations generate scripts that enable you to:

• Unload an entire database to external binary or ASCII files
• Copy selected tables, or all the tables, views, and procedures that you own to external binary or ASCII files
• Reload the database or objects from these files
• Export table data into XML format using the genxml utility
• Import XML data files into Ingres, using the xmlimport utility

Both the unload database and copy database operations are two-phase operations, as follows:

1. Create a script to unload or copy the table or database.
2. Execute the script to copy data out of a database and into another database.

Privilege Required for Unload Operation

To unload a database, you must be the DBA for the database or a privileged user impersonating the DBA.

Privilege Required for Copy Operation

To copy a database, you can be any user to copy selected tables or all the tables, views, and procedures that you own in the database.