The most efficient way to handle a statement is usually to hand off as much of the original statement as possible to the remote server involved. Sybase IQ will attempt to pass off as much of the statement as is possible. In many cases this will be the complete statement as originally given to Sybase IQ.
Sybase IQ will hand off the complete statement when:
Every table in the statement resides in the same remote server.
The remote server is capable of processing all of the syntax in the statement.
In rare conditions, it may actually be more efficient to let Sybase IQ do some of the work instead of passing it off. For example, Sybase IQ may have a better sorting algorithm. In this case you may consider altering the capabilities of a remote server using the ALTER SERVER statement.
For more information see the ALTER SERVER statement in Sybase IQ Reference Manual.
If you are writing queries that access tables in more than one database and you would like to divide the workload between servers, refer to the description of query processing within CIS in the section “Query processing” of the chapter “Understanding Component Integration Services” in the Component Integration Services User’s Guide for ASE and OmniConnect for more information.
