Database instance identifier

content/en/database_monitoring/database_identifier.md

@@ -0,0 +1,58 @@
+---
+title: Identifying Databases for Database Monitoring
+description: Understand how to identify your databases and hosts for DBM
+further_reading:
+- link: "/database_monitoring/"
+  tag: "Documentation"
+  text: "Database Monitoring"
+- link: "/database_monitoring/data_collected/"
+  tag: "Documentation"
+  text: "Data Collected"
+- link: "/database_monitoring/troubleshooting/"
+  tag: "Documentation"
+  text: "Troubleshooting"
+
+---
+
+## Database identifier
+Each database instance monitored with Datadog has a unique identifier. For Postgres, MySQL, SQL Server and Oracle this identifier can be configured using the `database_identifier.template` path in the integration configuration. Most users can leave this option as the default; it is primarily useful when multiple database instances are hosted on one machine.
+
+| Note that each instance will be billed as a host for Database Monitoring.
+
+## Reported hostname
+The `reported_hostname` configuration allows users to override the automatic resolution of `host` for a single database instance. This is useful when connecting to a database through a proxy, or when host resolution produces a different name than the one associated with the Datadog infrastructure host.
+
+
+## Examples
+
+Multiple Postgres instances each on different port:
+```
+database_identifier:
+  template: $resolved_hostname:$port
+```
+
+SQL Server host with multiple instances:
+```
+database_identifier:
+  template: $resolved_hostname:$instance_name
+```
+
+<!-- In 7.67 there will be new template variables and this can be updated to $azure_name/$database -->
+Azure pool:
+```
+database_identifier:
+  template: my-pool-name/my-database
+```
+
+MySQL instance with the same hostname running in multiple environments:
+```
+database_identifier:
+  template: $env-$resolved_hostname
+```
+
+Connecting to an Oracle database with multiple CDBs through a proxy:
+```
+reported_hostname: my-oracle.mydomain.com
+database_identifier:
+  template: $resolved_hostname\$cdb_name
+```