Review and perform pre-installation tasks before installing Oracle Application Express.
Before installing Oracle Application Express, Oracle recommends that you complete the following steps:
An alternative to shutting down the database is to prevent all users from accessing Oracle Application Express when upgrading your installation from a previous release of Oracle Application Express. Oracle only recommends this option in high availability production environments where planned outages are not available. For all other scenarios, the database should be shut down.
To disable user access to Oracle Application Express when the existing installation uses the Oracle HTTP Server with mod_plsql, you should either shut down the Web server or disable the Application Express Database Access Descriptor of the Web server.
Once you have prevented access from Oracle Application Express users, you should log in to SQL*Plus as
SYS, connecting to the database where Oracle Application Express is installed, and query
V$SESSION to ensure there are no long running sessions which would interfere with the upgrade process.
Oracle recommends that you create a backup of the current Oracle Database installation before you install Oracle Application Express. You can use Oracle Database Recovery Manager, which is included in the Oracle Database installation, to perform the backup.
After backing up the system, you must start the Oracle instance that contains the target Oracle Database. Do not start other processes such as a Web listener. However, if you are performing a remote installation, make sure the Web listener for the remote database has started.