In This Chapter

The onmode flags determine which of the following operations onmode performs:

• Change the database server operating mode.
• Force a checkpoint.
• Control the B-tree scanner.
• Change residency of the resident and virtual portions of shared memory.
• Switch the logical-log file.
• Kill a database server session.
• Add a shared-memory segment to the virtual shared-memory portion.
• Add or remove virtual processors.
• Regenerate a .infos file.
• Set decision-support parameters.
• Free unused memory segments.
• Override the WAIT mode of the ONDBSPACEDOWN configuration parameter.
• Enable large chunks and chunk offsets to a maximum size of 4 terabytes and allow up to 32,766 total chunks.
• Revert data to an earlier database server format.

  For information about migrating from or reverting to earlier versions of the database server, see the IBM Informix Migration Guide.

• Set data-replication options.
• Replicate an index with Data-Replication.
• Set SQL statement cache options.
• Dynamically set the value of the SET EXPLAIN statement
• Dynamically update the value of certain connection, PDQ, and memory configuration parameters.

If you do not use any options, the database server returns a usage statement.

On UNIX, you must be user root or user informix to execute onmode. On Windows, you must be a member of the Informix-Admin group.