[wenc]

Multidimensional calculations typically require a lot of aggregation, rotations (pivots) and joins.

Mongo is good for store-and-retrieve, and aggregation along a single dimension, and not as strong at the operations mentioned above.

Have you benchmarked Mongo against a relational db for analytic operations on a multidimensional model? The results could be interesting and perhaps different from what you would expect.[1]

Many new OLAP products are implemented on pure relational databases for performance reasons. Some databases with columnar indices are even faster for OLAP type operations.

[1] That said, Mongo could be a good choice for latency reasons. If your spreadsheet is doing lots of small calculations, then it makes sense to use something that can return results quickly.

[egeria_planning]

Egeria is not OLAP in the sense of analytics. It does not aggregate data. It computes formulas. Relational databases do not support this.