How to decide between Postgres and Cassandra?


I need to store 140 million of records. Each record will have around 10 fields, mostly reference to other types, integers, and date time. The number of records is expected to grow by 20 million per year.

Is the number of record too large for Postgres?



typically it is a good idea to put heavy volume data in Cassandra (e.g. Measurement data points). 140 million rows will definitely be very large for a single postgres table and imagine the number of reads / indexes / writes happening to these tables.



Also consider the type of queries you will be doing. Joins with referenes in Cassandra can be expensive… If it’s possible to put the realtional data as a smaller volume in postgres and the measurement/high volume data in cassandra, that would likely lead to better query performance.