Modern Oracle DBA

Oracle Data Guard for data protection and high availability. Knowing how to start and stop the Oracle Data Guard server is essential for database administrators. This document will explain the process step-by-step. Steps to Stop the DR Database Stop the Listener Copy lsnrctl stop <listener_name> Replace <listener_name> with the name of your database listener. This command stops the listener service that facilitates client connections to the database.   Cancel Managed Recovery Connect to the database using SQL*Plus and cancel the managed recovery process: Copy SQL>ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL; Database altered. This halts the recovery process for the standby database. Shutdown the Database Execute the following command to shut down the DR database: Copy SQL> SHUT IMMEDIATE; ORA-01109:database not open Database dismounted. ORACLE instance shut down. SQL> This...

  To check if your standby database is in sync with the primary database, follow these steps: 1.      Compare Sequence Numbers : Look at the latest sequence number generated on the primary database and the latest sequence number applied on the standby database. 2.      Check for Gaps : Ensure there are no missing sequence numbers on the standby database. The sequence numbers on both databases should match, and there should be no gaps in the sequence on the standby database. If they do match and there are no gaps, the databases are in sync. Verifying the Status of Primary and Standby Databases in Oracle On the Primary Server First, log in to the primary server and run the following SQL query to check the status: Copy Select name,open_mode,database_role from v$database; On the Standby Server Log in to the standby server and execute the same SQL query: Copy Select name,open_mode,database_role from v$datab...

1. Disk and File System Checks Objective: Monitor disk usage and verify file system configurations. Commands and Steps:   View Disk Space Usage: Command:  df -h Verify the available and used space in a human-readable format.   Check File System Configurations: Command:  cat /etc/fstab Ensure all required file systems are configured to mount at boot.   Verify Permissions of fstab File: Command:  ls -ld /etc/fstab Check permissions to ensure security and avoid unauthorized changes. 2. Network Configuration and Connectivity Objective: Validate DNS configurations and network routes. Commands and Steps:   Verify DNS Resolver Permissions: Command:  ls -ld /etc/resolv.conf   Display DNS Server Configuration: Command:  cat /etc/resolv.conf   Check Kernel Routing Table: Command:  ip route Confirm active routes for ...