This section contains commands for changing modes and information about how mode changes effect user sessions. Table 15 contains descriptions of each mode and shows which users can access the database server when the server is in each mode.
When the database server changes from offline mode to quiescent mode, the database server initializes shared memory. Only administrators can access the database server to perform maintenance functions that do not involve the execution of SQL and DDL statements.
When you move the database server from offline to online mode, the database server initializes shared memory and is available for all user sessions.
When you move the database server from off-line to single-user mode, you move the server into a mode that only administrators can use to perform database server functions and maintenance functions, including those involving the execution of SQL and DDL statements.
When you take the database server from quiescent mode to online mode, all sessions gain access.
If you have already taken the database server from online mode to quiescent mode and you are now returning the database server to online mode, any users who were interrupted in earlier processing must reselect their database and redeclare their cursors.
Take the database server gracefully from online mode to quiescent mode to restrict access to the database server without interrupting current processing.
After you perform this task, the database server sets a flag that prevents new sessions from gaining access to the database server. Current sessions are allowed to finish processing.
After you initiate the mode change, it cannot be cancelled. During the mode change from online to quiescent, the database server is considered to be in Shutdown mode.
Take the database server immediately from online mode to quiescent mode to restrict access to the database server as soon as possible. Work in progress can be lost.
A prompt asks for confirmation of the immediate shutdown. If you confirm, the database server sends a disconnect signal to all sessions that are attached to shared memory. If a session does not receive the disconnect signal or is not able to comply automatically within 10 seconds, the database server terminates the session.
The database server users receive either error message -459 indicating that the database server was shut down or error message -457 indicating that their session was unexpectedly terminated.
The database server cleans up all sessions that the database server terminated. Active transactions are rolled back.
The -y option eliminates the need to confirm the prompt.
When you move the database server from quiescent or online to single-user mode, you move the server into a mode that only administrators can use.
If you begin in online mode, the database server automatically disconnects any users who are connected with any user ID that is not user informix and the users receive an error message. If a connection is terminated during a transaction, the database server rolls back the transaction.
Change to single-user mode when you want to execute SQL and DLL commands when no other users are connected.
When you move the database server from single-user to online mode, all users can access the database server.
When you move the database server from single-user to quiescent mode, you move the server into a mode that only administrators can use to perform maintenance functions that do not involve the execution of SQL and DDL statements.
You can take the database server immediately from any mode to offline mode. After you take the database server to offline mode, restart the database server in quiescent, single-user, or online mode. When you restart the database server, it performs a fast recovery to ensure that the data is logically consistent.
A prompt asks for confirmation to go offline. If you confirm, the database server initiates a checkpoint request and sends a disconnect signal to all sessions that are attached to shared memory. If a session does not receive the disconnect signal or is not able to comply automatically within 10 seconds, the database server terminates this session.
The database server users receive either error message -459 indicating that the database server was shut down or error message -457 indicating that their session was unexpectedly terminated.
After you take the database server to offline mode, restart the database server in quiescent, single-user, or online mode. When you restart the database server, it performs a fast recovery to ensure that the data is logically consistent.
The database server cleans up all sessions that were terminated by the database server. Active transactions are rolled back.