What is the difference between materialized view in clickhouse and postgres

Question

I'm new to Clickhouse, and I was trying to use its materialized view feature. However, it seems that there are significant differences between Clickhouse's and Postgres' materialized views.

Answer 1

Yes, there are some differences between ClickHouse's and Postgres' materialized views.

One significant difference is that ClickHouse's materialized views are refreshed incrementally, while Postgres' materialized views are refreshed completely. In ClickHouse, when a materialized view is created, it starts with an empty dataset, and data is incrementally added to it as new data is inserted into the source table. In contrast, Postgres' materialized views are always populated with the entire data set of the source table at the time of the refresh.

Another difference is that ClickHouse's materialized views can be created with an arbitrary query, while Postgres' materialized views must be created with a SELECT statement. This means that ClickHouse's materialized views can include subqueries, joins, and other more complex constructs, while Postgres' materialized views are more limited in their functionality.

Finally, ClickHouse's materialized views can be used for distributed processing, which can help to improve performance in large-scale systems. Postgres' materialized views are more limited in their ability to handle distributed data processing.

Overall, while there are some similarities between ClickHouse's and Postgres' materialized views, there are also significant differences in their functionality and usage. It's important to carefully consider the requirements of your particular use case when choosing which system to use.