Ubuntu Informix如何使用

Installing Informix on Ubuntu

1. Create Informix User and Group:
   Informix requires a dedicated user and group for secure operation. Run the following commands as root:

   sudo groupadd informix
   sudo useradd -g informix -d /opt/informix -m informix
   sudo passwd informix
   

   This creates the informix group and user, with a home directory at /opt/informix.

2. Set Up Environment Variables:
   Switch to the informix user and edit the ~/.bash_profile file to configure essential environment variables:

   su - informix
   vi ~/.bash_profile
   

   Add these lines (adjust paths as needed for your Informix version):

   export INFORMIXDIR=/opt/informix
   export INFORMIXSERVER=myifxserver  # Unique name for your database server
   export ONCONFIG=onconfig.myifx     # Configuration file name
   export LD_LIBRARY_PATH=$INFORMIXDIR/lib:$LD_LIBRARY_PATH
   export PATH=$INFORMIXDIR/bin:$PATH
   

   Save the file and run source ~/.bash_profile to apply changes.

3. Download and Install Informix:
   Obtain the Informix Linux package from IBM’s official website. Extract it to /opt/informix:

   tar -xzf informix-<version>.linux-x86-64.tar.gz -C /opt/
   

   Change to the extracted directory and run the installer:

   cd /opt/informix
   sudo ./ids_install
   

   Follow the on-screen prompts to complete the installation.

4. Configure Database Parameters:
   Copy the sample configuration file and customize it:

   cd /opt/informix/etc
   cp onconfig.std onconfig.myifx
   vi onconfig.myifx
   

   Key parameters to modify:

   • ROOTNAME: Name of the root dbspace (e.g., rootdbs).
   • ROOTPATH: Path to the root dbspace file (e.g., /opt/informix/data/rootdbs).
   • ROOTSIZE: Initial size of the root dbspace (e.g., 100000 pages).
   • DBSERVERNAME: Must match INFORMIXSERVER in .bash_profile.

5. Prepare Database Storage:
   Create the root dbspace directory and file, then set correct permissions:

   mkdir -p /opt/informix/data
   touch /opt/informix/data/rootdbs
   chown informix:informix /opt/informix/data/rootdbs
   chmod 660 /opt/informix/data/rootdbs
   

6. Initialize and Start the Database:
   Stop any running database processes (if applicable) and initialize the database:

   onmode -ky  # Stop the database (if running)
   oninit -iv  # Initialize and start in interactive mode
   

   The -i flag initializes the database, and -v enables verbose output.

7. Verify Database Status:
   Use the onstat utility to check if the database is running:

   onstat -i
   

   Look for “Database selected” or “Server is up” in the output.

Connecting to Informix

1. Use dbaccess (Command-Line Tool):
   The dbaccess utility is the primary way to interact with Informix via the command line. Connect to your database:

   dbaccess myifxserver
   

   Replace myifxserver with your INFORMIXSERVER name. You’ll be prompted for the informix user’s password. Once connected, you can run SQL queries directly (e.g., SELECT * FROM systables;).

2. Connect via Application:
   For programmatic access (e.g., Python), use the Informix ODBC driver or libraries like ibm_db_sa. Example Python connection string:

   import ibm_db
   conn = ibm_db.connect("DATABASE=mydb;HOSTNAME=localhost;PORT=9088;PROTOCOL=TCPIP;UID=informix;PWD=yourpassword;", "", "")
   

   Adjust parameters (database name, hostname, port) to match your setup.

Managing Informix Services

1. Start the Database:
   Use onmode to start the database in normal mode:

   onmode -c all
   

2. Stop the Database:
   Gracefully shut down the database:

   onmode -ky
   

3. Restart the Database:
   Restart the database server:

   onmode -c reset
   

4. Check Server Status:
   Use onstat to monitor the server:

   onstat -  # Shows server status, memory usage, and active sessions
   onstat -d # Displays dbspace information
   

Key Notes for Success

• Permissions: Ensure all Informix directories (e.g., /opt/informix, /opt/informix/data) are owned by the informix user and have 660 permissions for files.
• Ports: Verify that required ports (e.g., 9088 for TCP/IP) are open in your firewall. Update /etc/services if necessary to define custom ports.
• Configuration Files: Regularly back up onconfig.myifx and sqlhosts (located in /opt/informix/etc) to avoid losing custom settings.
• Logs: Check /opt/informix/logs for error logs if you encounter issues during startup or operation.

For advanced configurations (e.g., remote access, replication), refer to IBM’s official Informix documentation for Ubuntu-specific guidance.