[manigandham]

Isn't adding a column even easier in column-oriented OLAP databases?

I agree that more complex row formats are needed though. Bigquery has done well with nested/repeating structures and Snowflake uses the PAX data format for JSON which has been very useful (however their JSON/VARIANT column doesn't support structured types).

[hodgesrm]

It's definitely easier than conventional RDBMS. Adding a column in ClickHouse is just a metadata operation. BiqQuery has great nested structure support.

Still, it's hard to beat MongoDB in this respect. In my first app I was amazed that I could just insert a BSON object and MongoDB created a queryable table automatically. You pay for it of course in other ways but the ease of use is quite extraordinary.