If you know all your access pattern and your writes >>> reads, a NoSQL solution will be cheaper to operate than Postgres. Meaning, I believe, for most deployments, you can get the same amount of performance from postgres, but simply at a higher cost (which may be 3-6x at most). Another reason to go with NoSQL is if you are latency sensitive, although I don't think Dynamo falls in this bucket.
NoSQL was also really good for OLAP, but I think now there are several really good OLAP solutions (like Clickhouse for OSS and Redshift/BigQuery in the cloud) that are easier to manage.
If you know all your access pattern and your writes >>> reads, a NoSQL solution will be cheaper to operate than Postgres. Meaning, I believe, for most deployments, you can get the same amount of performance from postgres, but simply at a higher cost (which may be 3-6x at most). Another reason to go with NoSQL is if you are latency sensitive, although I don't think Dynamo falls in this bucket.
NoSQL was also really good for OLAP, but I think now there are several really good OLAP solutions (like Clickhouse for OSS and Redshift/BigQuery in the cloud) that are easier to manage.