Informix Database Operating Mode:

Informix Database Server Operating Mode:

Below are the  four principal modes of operation of the database server:

OFFLINE  <==>  Quiescent  <==>  Single User <==> ONLINE

• ONLINE: Users can connect with the database server and perform all database activities. This is normal operating mode of the database server.

• OFFLINE: When the database server is not running. No shared memory is allocated.Only the administrator (user informix) can change from this mode to another mode.

• Administration mode: Single user modeThis option brings the database server to administration mode, allowing the informix user all functions including the issuance of SQL and DDL commands. The -j -U option enables the DBSA to designate specific users (in addition to the informix user) to access the database server.

One or more users who have administration mode access User informix or a DBSA can dynamically give one or more specific users the ability to connect to the database server in administration mode through the onmode -j command, the oninit -U command, or the ADMIN_MODE_USERS configuration parameter.

 

Other users can view database-server status information, but they cannot access the database server.

• Quiescent mode: Database-server processes are running and shared-memory resources are allocated.only administrators can access the database server to perform maintenance functions that do not involve the execution of SQL and DDL statements.

Other users can view database-server status information, but they cannot access the database server.

In addition, the database server can also be in one of the following modes:

• Read-only mode is used by the secondary database server in a data replication environment. An application can query a secondary database server that is in read-only mode, but the application cannot write to a read-only database.
• Recovery mode is transitory. It occurs when the database server performs fast recovery or recovers from a system archive or system restore. Recovery occurs during the change from offline to quiescent mode.
• Shutdown mode is transitory. It occurs when the database server is moving from online to quiescent mode or from online (or quiescent) to offline mode. For the current users access the system, but no new users are allowed access.

After shutdown mode is initiated, it cannot be canceled.

Below Matrix are various commands to switch the database Mode:

	Online	Offline	Quiescent	Single/Admin
Online	--	onmode -ky (or) onmode -k	Gracefully: onmode –s (or) onmode –sy Immediate: onmode –u (or) onmode -uy	onmode –j
Offline	oninit -v  (or) oninit -yv	--	oninit –s	oninit –j
Quiescent/ Maintenance	onmode -m	onmode –ky (or) onmode -k	--	onmode –j
Single User / Administrative	onmode  -m	onmode -k	onmode -s (graceful) onmode -u (Immediate)	--