The onunload and onload utilities

The onunload and onload utilities provide the fastest way to move data between computers that use the same database server on the same platform.

For example, your site purchases a more powerful UNIX computer to allow faster access for users. You need to transfer existing databases to the new database server on the new computer. Use onunload to unload data from the first database server and then use onload to load the data into the second database server. Both database servers must have the same version number, or they must have compatible version numbers. You can move an entire database or selected tables only, but you cannot modify the database schema.

The onunload utility can unload data more quickly than either dbexport or the UNLOAD statement because onunload copies the data in binary format and in page-sized units. The onload utility takes a tape or a file that the onunload utility creates and re-creates the database or the table.

The onunload and onload utilities are faster than dbimport, dbload, or LOAD but are much less flexible and do not let you modify the database schema or move from one operating system or database server version to another.


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