OraEasy

Introduction AWR (Automatic Workload Repository) is an Oracle performance monitoring feature that collects, processes, and stores database performance statistics. These statistics are used for problem diagnosis and self-tuning of the database. The collected data can be viewed through database views or generated as HTML or text reports, helping DBAs analyze the current performance state of the database in detail. Background Processes for AWR MMON : collects AWR statistics. MMNL : writes ASH and AWR data to disk. Data Collected by AWR AWR captures a wide range of performance-related metrics, including: Object statistics: access and usage statistics of database segments. Time model statistics: data from the V$SYS_TIME_MODEL and V$SESS_TIME_MODEL views. System and session statistics: selected statistics from the V$SYSSTAT and V$SESSTAT views. Active Session History (ASH) statistics. High-load SQL statements contributing significantly to database workload. Prerequ...

Introduction A switchover is a role reversal between the primary database and one of its standby databases. In this article we will see how to perform a switchover activity in a Logical Standby setup. Prerequisites Logical standby should be configured and in sync. 30 mins downtime at database end. Environment Used in this Guide Server Primary Standby Hostname dcdb.oraeasy.com drdb.oraeasy.com OS OEL 9 OEL 9 SID ORADBDC ORADBDR Service Name ORADBDC ORADBDR Switchover Activity Step by Step Step 1: Check the Sync Between Primary and Standby Confirm the logical standby is fully caught up before starting a switchover. Attempting one against a lagging standby risks data loss or an extended outage. Primary: SQL> select name,db_unique_name,database_role,open_mode from v$database; NAME DB_UNIQUE_...

Introduction In this article, we will see how to configure a Shared Listener in Oracle Database. It is especially beneficial in environments with many light or intermittent user connections, such as web or application servers. Type of Server Dedicated Server: Provides one server process per session, offering maximum performance and isolation but using more memory. Shared Server: Allows multiple clients to share a pool of server processes, providing scalability and memory savings but introducing some queue-related latency. Parameters The following parameters need to be configured for a Shared Listener. All of them can be modified dynamically without bouncing the database instance. DISPATCHERS : specifies one or more dispatcher processes that handle incoming client connections in a Shared Server configuration. LOCAL_LISTENER : specifies how the database locates the listener running on the local machine. It ensures the instance registers properly with the listener so cli...

Introduction Oracle Logical Standby database is a type of standby database created and maintained using Oracle Data Guard (ODG), where redo data from the primary database is transformed into SQL statements and applied logically on the standby database. A Logical Standby differs from a Physical Standby by applying redo through SQL Apply rather than block-level recovery. This approach keeps the standby database open in read/write mode while it remains in sync with the primary. Logical Standby databases are particularly well suited for environments that require both robust data protection and effective workload offloading, without adding performance overhead to the primary system. In this article, we will configure the Logical Standby. Prerequisites Oracle Data Guard (Physical Standby) should be configured. For Physical Standby Setup click here . Verify the unsupported objects for Logical Standby. Tables must have a primary key or unique constraint. Environment Used in this ...