Oracle7 Server Utilities

Loading Data Across Different Operating Systems

When a datafile is created on one operating system that is to be loaded under a different operating system, the data must be written in a form that the target system can read. For example, if the source system has a native, floating-point representation that uses 16 bytes, and the target system's floating-point numbers are 12 bytes; then there is no way for the target system to directly read data generated on the source system. One solution is to load data across a SQL*Net link, taking advantage of the automatic conversion of datatypes. This is the recommended approach, whenever feasible.

In general, the problems of inter-operating system loads occur with the native datatypes. Sometimes, it is possible to get around them by padding a field with zeros to lengthen it, or reading only part of the field to shorten it. (For example, when an 8-byte integer is to be read on a system that uses 6-byte integers, or vice versa.) Frequently, however, problems of incompatible byte-ordering, or incompatible implementations of the datatypes, make even this approach unworkable.

Without a SQL*Net link, it is a good idea to use only the CHAR, DATE, and NUMERIC EXTERNAL datatypes. Datafiles written in this manner are longer than those written with native datatypes. They take more time to load, but they transport most readily across operating systems. However, where incompatible byte-ordering is an issue, special filters may still be required to reorder the data.

Trusted Oracle7

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