Creating Deleting and Modifying Services in Oracle RAC

1.Creating Service in Oracle RAC : Step 1: To create a service in Oracle RAC

Here I have created service named myservice with preferred instance orcl1 and available instance orcl2. To check all available parameters of service creation :

Step 2: Check the status of service :

We can see here service […]

Read More

Network link in expdp

The export operation is performed with data that is consistent up to the specified SCN. If the NETWORK_LINK parameter is specified, then the SCN refers to the SCN of the source database. Follow following steps to the export database using network-link. Source database: demo Target database: uat Database platform : 11.2.0.4.0 Step 1 : Create a tnsnames.ora […]

Read More

Fast Application Notification [FAN] overview

As the Oracle docs say, The Oracle RAC, FAN, Oracle 12c Fast Application Notification (FAN) feature provides a simplified API for accessing FAN events through a callback mechanism. This mechanism enables third-party drivers, connection pools, and containers to subscribe, receive and process FAN events. These APIs are referred to as Oracle RAC FAN APIs. If […]

Read More

Grid Naming Service in Oracle RAC

When we use Oracle RAC, all clients must be able to reach the database. All public addresses, VIP addresses and SCAN addresses of Cluster must be resolved by the clients.And GNS[Grid Naming Service] helps us resolve this problem. GNS is linked to the domain name server (DNS) so that clients can resolve these dynamic addresses […]

Read More

Miscellaneous Oracle RAC wait events

Miscellaneous Oracle RAC wait events 1. gc remaster : resource remastering happens based on 2 situation : 1.When Instance leaves or joins cluster. 2.Dynamic remastering from a less busy instance to an instance where demand for that object is too high.This is also called resource affinity. 2. gc cr grant busy : The gc cr […]

Read More

Rebootless node fencing in Oracle RAC

Oracle Grid Infrastructure 11.2.0.2 has many features including Cluster Node Membership, Cluster Resource Management, and Cluster Resources monitoring. One of the key areas where DBA need to have expert knowledge on how the cluster node membership works and how the cluster decides to take out node should there be a heartbeat network, voting disk or […]

Read More

Types of Supplemental logging at Database level

Redo log files are generally used for instance recovery and media recovery. The data needed for such operations is automatically recorded in the redo log files. However, a redo-based application may require that additional column be logged in the redo log files. The process of logging these additional columns is called supplemental logging. There are two […]

Read More

Node eviction in Oracle RAC

Node eviction is quite sometimes happening in Oracle RAC environment on any platform and troubleshooting and finding root cause for node eviction is very important for DBAs to avoid same in the future. There can be many reasons behind node eviction like , Network Heartbeat Missed Voting Heartbeat Missed CSSD Agent/ Monitor hung RDBMS instance […]

Read More

Split Brain and Amnesia in Oracle RAC

Split Brain and Amnesia Two types of problems can arise from cluster partitions: split brain and amnesia. Split brain occurs when the cluster interconnect between hosts is lost and the cluster becomes partitioned into subclusters, and each subcluster believes that it is the only partition. A sub-cluster that is not aware of the other subclusters […]

Read More

Oracle RAC Cache Fusion

Cache Fusion is one of the most Important concepts in Oracle RAC. As we know each and every instance of RAC cluster is having its own local buffer cache where it does cache functionality.But when multiple users are connected to different nodes , a need to access or lock a data block owned by other […]

Read More