Hi @Kranthi Gurajapu ,
If it’s PostgreSQL on VM then you would have to configure monitoring by leveraging data sources in Azure Monitor. I see CollectD PostgreSQL plugin as the suitable data source in case it is Linux machine. Check this document for details regarding CollectD configuration. On the other hand, you can also accomplish up to some extend by configuring using Azure Monitor with the HTTP Data Collector API / Azure Monitor Custom Logs.
If it’s Azure Database for PostgreSQL then it is recommended way and is directly supported by Azure Monitor. You can Monitor and tune Azure Database for PostgreSQL - Single Server and Monitor and tune Azure Database for PostgreSQL - Hyperscale (Citus). You may also find the list of metrics supported here.