Contents Index Resending messages The encoding scheme

SQL Remote User's Guide
  SQL Remote Administration

Encoding and compressing messages


As messages pass through e-mail 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, carrying out 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:

Settings for compatibility 

To be compatible with previous versions of the software, you should set the database option COMPRESSION to be -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 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 COMPRESSION 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

Contents Index Resending messages The encoding scheme