OraEasy

Introduction: A Refreshable Clone PDB is a special type of Pluggable Database introduced in Oracle Database 12.2 that allows you to periodically synchronize a cloned PDB with its source by applying redo data. In this article, we will configure the Refreshable Clone PDB. Refresh Mode : Automatic Refresh Mode : This refresh mode is a configuration of a refreshable clone PDB in Oracle Database where the clone is automatically synchronized with its source PDB at fixed, predefined time intervals. The refresh occurs based on the interval specified in the REFRESH MODE EVERY n MINUTES clause during creation or modification of the clone. Manual Refresh Mode : This refresh mode is a configuration of a refreshable clone PDB in Oracle Database where synchronization with the source PDB occurs only when explicitly initiated by the DBA. The clone is created using the REFRESH MODE MANUAL clause and refreshed on demand using the ALTER PLUGGABLE DATABASE pdb_name REFRESH co...

Introduction: Oracle Logical Standby Database can be used for write opeartion if required to do reports and test any statement. Although if the same transaction got executed on Primary then it will create conflict and SQL apply got abrupt on Standby, hence it will result in out of sync between Primary & Standby. In this article, we will see how to resolve such issue by skipping the transaction. Prerequisites: Logical standby should be configured and in sync. Environment: Server Primary Standby Hostname drdb.oraeasy.com dcdb.oraeasy.com OS OEL 9 OEL 9 SID ORADBDR ORADBDC Service Name ORADBDR ORADBDC Now proceed to create the issue scenario and its resolution step by step: 1. Check the sync between Primary and Standby. ==> Primary: SQL> select name,db_unique_name,databas...

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 V$SYS_TIME_MODEL and V$SESS_TIME_MODEL views. System and Session Statistics: Selected statistics from V$SYSSTAT and V$SESSTAT views. Active Session History (ASH) statistics. High-load SQL statements contributing significantly to database w...

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 do Switchover activity in Logical Standby setup. Prerequisites: Logical standby should be configured and in sync. 30 mins downtime at database end. Environment: Server Primary Standby Hostname dcdb.oraeasy.com drdb.oraeasy.com OS OEL 9 OEL 9 SID ORADBDC ORADBDR Service Name ORADBDC ORADBDR Now proceed to Switchover activity step by step: 1. Check the sync between Primary and Standby. ==> Primary: SQL> select name,db_unique_name,database_role,open_mode from v$database; NAME DB_UNIQUE_NAME DATABASE_ROLE OPEN_MODE --------- ------------------------------ ---------------- -------------------- ORADB oradbd...

Introduction: In this article, we will see how to configure 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: It provides one server process per session, offering maximum performance and isolation but using more memory. Shared Server: It allows multiple clients to share a pool of server processes, providing scalability and memory savings but introducing some queue-related latency. Parameters: Below parameters are need to configure for Shared Listener. DISPATCHERS: It specifies one or more dispatcher processes that handle incoming client connections in a Shared Server configuration. LOCAL_LISTENER: It specifies the database how to locate the listener running on the local machine. It ensures the instance registers properly with the listener so clients can connect using shared server, dedicated server,...