There's no specific or standard computation on Postgres database performance running On-Prem and Cloud. It depends on the workload. Most of the cloud vendor provides pre-configured setup in terms of number of CPU, RAM, Storage, Network Bandwidth, etc. Usually, doing a performance or load testing will give the optimal configuration to meet the performance requirement.
There is no limitation of the database size. However, there are customer cases where Postgres is being used for storing Petabyte's size of data. Like any other proprietary database in the market, PostgreSQL can handle TBs of data. The hardware layer is one of the critical components in database sizing.
It's in Asynchronous mode only.
pgBackRest repositories can be in S3, Azure, and GCS compatible object stores to allow the virtually unlimited capacity and retention. Unfortunately, BART & BARMAN cannot directly support store backup on Azure Blob storage.
pgBackRest can encrypt the repository to secure backups wherever stored, while other backup tools like BARMAN & BART don't have any encryption features.
Bi-Directional Replication (BDR) is an asynchronous multi-master replication system for PostgreSQL, specifically designed to allow geographically distributed clusters. Multi-Master Replication in BDR allows efficient replication for both DDL and DML with automatic conflict resolution. It also offers Conflict-free Replicated Data Types (CRDTs), which support merging values from concurrently modified rows.
Yes, you can use all these tools with open-source PostgreSQL. BART is EnterpriseDB subscription-based tool.
All the EnterpriseDB tools are subscription-based.
Yes, EDB provides an additional extension developed and maintained by EDB team. Please refer to the link, Extensions supported by EDB. https://www.enterprisedb.com/edb-docs/d/postgresql/reference/manual/11.2/contrib.html