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cassandranosqlrdbms

Is RDBMS with redundancy as good as nosql dbs?

I am reading about NoSQL DBs (Specifically Cassandra) and It says that Cassandra is faster for writing and queries are fast as well. Schema design is done more based on queries than based on data. For example, You have queries like in this example

then I have a question, Suppose I design the RDBMS schema similar to Cassandra's way and I ensure that no joins are required for queries. Will I get any significant performance gains still by using Cassandra(NoSql DBs)?

Solution

  • Cannot have an exact answer but few points,

    1. JOIN is just of the many things - Cassandra stores the data physically based on the partition keys and hence making the read by partition as fast as possible.
    2. On the performance side - its not about the performance at the beginning but keeping the performance consistent over a period of time. Say for example you have a time series like requirement where data is inserted every second, RDBMS performance will usually degrade as the data grows and not easy to keep up the index and stats up to date etc, while cassandra will fit better for a time series pattern and as the data grows its easy to scale up by adding nodes.
    3. On the write performance - Cassandra's write workflow itself is different and is designed in a way to take up faster (the complicated process like merging sstabls, compaction etc happens in the background without affecting the actual write).

    In short - you need to review the business case and make decision.