SQL Remote installations include a consolidated database and many remote databases, together with a Message Agent at each site.
At each site, the Message Agent handles the sending and receiving of messages. The messages take the form of SQL statements, and the database server handles the actual execution of those SQL statements.
The upgrade requirements for SQL Remote are as follows:
Upgrade your databases You must upgrade the database file format by unloading and reloading your database.See Upgrading SQL Anywhere.
Software upgrades can be one site at a time Version 5 Message Agents can exchange messages with version 10 Message Agents, as long as the compression database option is set to a value of -1 (minus one). There is no need to upgrade software throughout the installation simultaneously.See compression option [SQL Remote].
Message Agent and server can be upgraded separately The Message Agent is an embedded SQL application. Therefore, the database server can be upgraded before the Message Agent as long as the compatibility library is used. It is, however, recommended that you upgrade your Message Agent at the same time as the database server for performance reasons.The Message Agent cannot be upgraded before the database server, as a new client application cannot work with a version 5 server.
One approach to upgrading is as follows:
Upgrade the consolidated database server and Message Agent. Set the compression database option to -1 so that all messages are compatible with the version 5 software at remote sites.
Upgrade remote database servers and Message Agents. You can set the compression database option to a value other than -1 to take advantage of compression and encoding on messages being sent to the consolidated database server.
When all remote database servers and Message Agents are upgraded, set the compression database option at the consolidated site to a value other than -1.