Would RisingWave and PostgreSQL both be used in any scenarios?

[omnipresent07]

Does running risingwave in a ecosystem remove the need to have PostgreSQL running? Would there ever be scenarios where both are run simultaneously?

[yingjunwu]

Hi @omnipresent07 - we do see many people using both RisingWave and Postgres.

RisingWave is not built for transaction processing (see: https://docs.risingwave.com/docs/current/transactions/). So if you want to process transactions, you may want to use a PostgreSQL. RisingWave can consume PostgreSQL CDC and perform real-time streaming analytics.

The data stack may look like:

Your APP -> PostgreSQL (for transaction processing) -> RisingWave (for streaming analytics) -> Grafana/Metabase/Superset/whatever (for visualization)

But if you don't really need to do transaction processing, you may consider using RisingWave to replace PostgreSQL, especially for data streaming scenario. For example, when people use streaming processors like Flink/Samza/Storm, they typically want to use PostgreSQL/MySQL to serve queries. The data stack may look like:

Your APP -> Kafka -> Flink/Samza/Storm (for stream processing) -> PostgreSQL (for serving queries) -> Grafana/Metabase/Superset/whatever (for visualization)

or

Your APP -> PostgreSQL (for transaction processing) -> Flink/Samza/Storm (for stream processing) -> PostgreSQL (for serving queries) -> Grafana/Metabase/Superset/whatever (for visualization)

But using RisingWave, the data stack can be simplified to:

Your APP -> kafka -> RisingWave -> Grafana/Metabase/Superset/whatever (for visualization)

or

Your APP -> PostgreSQL (for transaction processing) -> RisingWave -> Grafana/Metabase/Superset/whatever (for visualization)

Please feel free to let me know if you have any questions.