DBA NAVIGATOR

Mastering Oracle Clusterware Administration: Essential Commands & Best Practices Oracle Clusterware is a key component for managing cluster environments, ensuring high availability and resource management for Oracle databases. Below are essential commands for managing Oracle Clusterware effectively. What is crsctl? crsctl (Cluster Ready Services Control) is a command-line utility provided by Oracle to manage Oracle Clusterware. It allows administrators to start, stop, check, and configure various aspects of cluster services. With crsctl , DBAs can control cluster resources, manage voting disks, check the status of Oracle High Availability Services, and ensure the proper functioning of Oracle RAC environments. Starting and Stopping Oracle Clusterware On Local Node Stop Clusterware: crsctl stop cluster Start Clusterware: crsctl start cluster On RAC Standalone/Oracle Restart Stop Cluster: crsctl stop has Start Cluster: crsctl start has On All Nodes or All Hub Nodes Start Clusterware:...

 Managing database access efficiently while maintaining security is a critical task for database administrators (DBAs). Oracle Database provides a powerful feature called Proxy Authentication , allowing users to connect through a proxy user without directly using the target user's credentials. This mechanism enhances security, streamlines user management, and facilitates auditing. This article explores Oracle Proxy Users, their benefits, and step-by-step instructions to create and manage them effectively. What is an Oracle Proxy User? A Proxy User is an intermediary user in Oracle Database that allows another user (client user) to connect to the database through it. This eliminates the need for sharing passwords while still enabling proper authentication and authorization. Use Cases for Proxy Users Application Connection Pooling – Applications can use a single proxy user to manage multiple user sessions securely. Security and Access Control – Users can connect via a proxy withou...

  Oracle Data Guard allows database administrators to create a physical standby database to ensure high availability and disaster recovery. However, in certain scenarios, it is necessary to temporarily convert a physical standby database to a snapshot standby database for testing or development purposes. This guide provides step-by-step instructions on how to perform this conversion and revert it back to a physical standby database. Converting Physical Standby to Snapshot Standby DATABASE NAME: STANDBY INSTANCES:  STANDBY1, STANDBY2 Step 1: Check the Current Standby Status SELECT status, instance_name, database_role, open_mode FROM v$database, gv$Instance; STATUS       INSTANCE_NAME    DATABASE_ROLE    OPEN_MODE ------------ ---------------- ------------------------------------- -------------------- OPEN                  standby1                  ...

 Ensuring business continuity requires regular Disaster Recovery (DR) drills. This guide covers the Switchover and Switchback process between Primary (DC) and Standby (DR) databases . Pre-checks Before Performing Switchover Before starting the activity, ensure there are no active sessions in the database. If any are found, share the session details with the application team, get their confirmation, and terminate the sessions. Primary Database Name: PRIMARY Standby Database Name: STANDBY  Identify Active Sessions set lines 999 pages 999 col machine for a30 col username for a30 col program for a30 compute sum of count on report break on report select inst_id,username,osuser,machine,program,status,count(1) "count" from gv$session where inst_id=1 and program like 'JDBC%' group by inst_id,username,osuser,machine,program,status order by 1,2; select inst_id,username,osuser,machine,program,status,count(1) "count" from gv$session where inst_id=2 and program lik...

 Adding a Disk to existing ASM disk group: Before proceeding with the below steps, capture the ASM current utilization details by using the below query. SELECT NAME, TOTAL_MB/1024 total_gb, FREE_MB/1024 free_gb, ROUND((1- (FREE_MB / TOTAL_MB))*100, 2)  "percentage used" FROM v$asm_diskgroup order by 4 desc / NAME                       TOTAL_GB    FREE_GB       percentage used ------------------------------ ---------- ---------- --------------- DATA                          8388.75781   146.347656        98.26 INDX                          4144.38281   78.4140625        98.11 OCR                            24.9414063   10.64...