By allowing only a single write server, Sybase IQ multiplex eliminates the overhead and scalability limits of a distributed lock manager. As it completes transactions that modify data in the IQ Store, the write server must communicate information about new table versions to the query servers. A multiplex accomplishes this using table version logging while the servers continue to run.
Query servers continue to run while the write server issues DDL operations and the DDL operations are logged in the table version log (TLV log). The write server preserves older table versions for as long as needed. In single node mode, no version logging takes place. Query servers cannot run and must be synchronized to restart.
