What is Management database MGMGT in Oracle

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 While I was working with oracle 11G cluster ware I used to come across a term called cluster health check monitor which actually helps us to analyze the cluster ware statistics. However this feature is optional as it used to consume more CPU and it is integral part of oracle database 11g where the data is maintained in Berkeley database.

From Oracle 12.1.0.2, MGMTDB is a mandatory database installed by Oracle itself.

The MGMTDB is a built-in database to store Grid Infrastructure Management Repository (GIMR). This repository enables such features as Cluster Health Monitor(aka CHM/OS, ora.crf), Oracle Database QoS Management, and Rapid Home Provisioning, and provides a historical metric repository that helps in  viewing of past performance and diagnosis of issues.

Management Repository is a single instance database that's managed by Oracle Clusterware in 12c. The database will be automatically failed over to other node in case of node evictions. In 12.2, MGMTLSNR also listens on public network, therefore ora.MGMTLSNR has dependency on VIP resource type, both MGMTLSNR and MGMTDB will failover when public network is down.

In 12.1.0.1, GIMR is optional, if Management Database is not selected to be configured during installation/upgrade, all features (Cluster Health Monitor (CHM/OS) etc) that depend on it will be disabled.

This changed in 12.1.0.2, it's mandatory to have GIMR and it's not supported to be turned off with the exception of Exadata.



Thank you 

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