Encoding and compressing messages

As messages pass through email and other message systems, there is a danger of them becoming corrupted. For example, some message systems use certain characters or character combinations as control characters.

Message size affects the efficiency with which messages pass through a system. Compressed messages can be processed more efficiently by a message system than uncompressed messages. On the other hand, compression can itself take a significant amount of time.

SQL Remote encoding and compression

SQL Remote has a message encoding and compression scheme built in to the Message Agent. The scheme provides the following features:

  • Compatibility   The system can be set up to be compatible with previous versions of the software.

  • Compression   You can select a level of compression for your messages.

  • Encoding   SQL Remote encodes messages to ensure that they pass through message systems uncorrupted. The encoding scheme can be customized to provide extra features.

Settings for compatibility

To be compatible with previous versions of the software, you should set the compression database option to -1 (minus one) at each database running the Version 6 software. This setting ensures that messages are sent out in a format compatible with older versions of the software.

Upgrading SQL Remote

If you upgrade the consolidated database Message Agent first, you should set its compression database option to -1. As each remote site in your replication system is upgraded to Version 6, you can change its setting of the compression database option to a value between 0 (no compression) and 9 (maximum compression). This allows you to take advantage of compression features on messages being sent to the consolidated database. Once all remote sites are upgraded, you can set the consolidated site Message Agent compression option to a value other than -1.

In addition, setting the compression option to a value other than -1 allows you to take advantage of the Version 6 message encoding improvements.


The encoding scheme
Creating custom encoding schemes