I am working on a SQL query engine for multi-dimensional and hierarchical analysis compatible with Apache Spark, ClickHouse, BigQuery, Snowflake, PostgreSQL and DuckDB. GitHub https://github.com/squashql/squashql Website https://www.squashql.io/

I fully agree. This is why I created a SQL query engine for my own need few years ago, it is not open-sourced. It is called SquashQL (https://github.com/squashql/squashql). It provides a "simple" API (available in Typescript and Java for now) to perform "complex" and "dynamic" SQL queries such as pivot queries, standard queries with rollups or partial rollups with the ability to hide totals and subtotals, time-series and hierarchical comparison, bucketing, drilling across and more...