Separation of Duty for Administering Oracle Real Application Clusters. Starting with Oracle Database 12c Release 2, Oracle Database provides support for separation of duty best practices when administering Oracle RAC by introducing the SYSRAC administrative privilege for the clusterware agent. This feature removes the need to use the powerful SYSDBA administrative privilege for Oracle RAC. […]
Archives for April 2021
Oracle Grid 12c: Read Only Instances on Leaf Nodes
Starting with Oracle Grid Infrastructure 12c Release 2, it is now possible to run read-only instances on Leaf nodes. Oracle Grid Infrastructure 12c introduced the concept of Oracle Flex cluster in which nodes can be classified as a Hub node or a Leaf node. In Oracle Grid Infrastructure12c Release 1, database instances could only be […]
Background Processes Specific to Oracle RAC
An Oracle RAC database has the same processes and memory structures as a single-instance Oracle database and additional process and memory structures that are specific to Oracle RAC. The global cache service and global enqueue service processes, and the global resource directory (GRD) collaborate to enable cache fusion. The Oracle RAC processes and their identifiers […]
How to Create and Manage Snapshot Standby Database
Snapshot Standby Databases: Overview A snapshot standby database is a fully updatable standby database that is created by converting a physical standby database to a snapshot standby database. A snapshot standby database receives and archives—but does not apply—redo data from a primary database. Redo data received from the primary database is applied when a snapshot […]
How to disable ACPI in CentOS/RHEL 7
ACPI stands for Advanced Configuration and Power Interface. It is the system that controls hardware actions such as the dynamic speed fans, the power button behavior, system sleep states, and helps to identify some system capabilities. ACPI power-saving features are hierarchical, meaning that any device running “behind” another will be dependent on the power state […]
How to Use real-time query to access data on a physical standby database
Oracle Active Data Guard Oracle Active Data Guard increases performance, availability, data protection, and return on investment wherever Data Guard is used for real-time data protection and availability. An Oracle Active Data Guard standby database can be used to offload a primary database of reporting, ad hoc queries, data extracts, and backups, making it a […]
CentOS/RHEL 8: “ACPI MEMORY OR I/O RESET_REG” Server Hung after reboot
The Problem Rebooting the CentOS/RHEL 8 server causes it to freeze. From the console output, the system is stuck at: … [ 68.906159] dracut: Disassembling device-mapper devices Rebooting. [ 68.934073] kvm: exiting hardware virtualization [ 68.936622] sd 0:0:0:0: [sda] Synchronizing SCSI cache [ 68.938942] e100e: EEE TX LPI TIMER: 00000011 [ 69.018502] reboot: Restarting system […]
How to Create a Physical Standby Database by Using SQL and RMAN Commands
You perform the steps listed below when using SQL and RMAN commands to create a physical standby database. These are high level steps and are explained in detail later in the blog. Prepare the primary database. Set parameters on the physical standby database. Configure Oracle Net Services. Start the standby database instance. Execute the DUPLICATE […]
Basics of client connectivity in Oracle Data Guard configuration
Oracle Net Services Overview Oracle Net Services provide enterprise-wide connectivity solutions in distributed, heterogeneous computing environments. It enables a network session from a client application to an Oracle Database server. A dedicated server process is a type of service handler that the listener starts when it receives a client request. The slide depicts the process […]
ORA-354 ORA-353 and ORA-312: Possible corruption in Online Redo Log File Members in a Redo Log Group
The Problem Following errors are reported in the alert log file: ORA-354: corrupt redo log block header ORA-353: log corruption near block %s change %s time %s ORA-312: online log %s thread %s: ‘%s’ ORA-312: online log %s thread %s: ‘%s’ ORA-312 reports all the redo log file names for the same redo log group […]