# pentaho/mondrian

Mondrian is an Online Analytical Processing (OLAP) server that enables business users to analyze large quantities of data in real-time.

Repository: https://github.com/pentaho/mondrian
Canonical: https://ross.abutalabs.com/products/pentaho-mondrian
Homepage: http://mondrian.pentaho.com/
Language: Java
License: NOASSERTION
License Family: other
Topics: mondrian, olap, java, mdx, database
Last push: 2026-08-26T02:59:01+00:00

## Health v2 (maintenance only)
Score: 77/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 35, longevity 100
- inputs: {"age_days": 5280, "days_push": 7, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases, no_license
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1174, forks 722 (observed 2026-08-28T04:03:52.289748+00:00)

## What it is
Mondrian is an open-source OLAP (Online Analytical Processing) server written in Java that lets business users analyze large volumes of relational data in real time using MDX queries. It includes a core Java library and a desktop Workbench GUI for designing OLAP schemas.

## Use cases
- run MDX queries against relational data warehouses
- serve multidimensional analytics to BI tools
- define OLAP cubes and schemas over SQL databases
- perform real-time slice-and-dice analysis of large datasets
- build a ROLAP server on top of an existing database
- design and test Mondrian schemas with a GUI workbench

## When to choose
- you need an open-source OLAP engine speaking MDX over relational databases
- your BI stack (e.g., Pentaho) requires a Mondrian-compatible OLAP server
- you want multidimensional aggregation and caching on large SQL datasets

## When to avoid
- you only need simple SQL reporting without multidimensional modeling
- you want a lightweight embedded analytics library rather than a server
- your team has no MDX/OLAP expertise and prefers modern columnar engines like ClickHouse or DuckDB

## Facets
- artifact type: library
- maturity: active
- function: database, search-engine, developer-tools
- domain: databases, analytics, big-data, data-science
- platform: jvm, cross-platform
- tags: olap, mdx, business-intelligence, data-warehouse, rolap

## Member repositories
- pentaho/mondrian (main) score 77

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:03:52.289748+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T06:28:18.639042+00:00, confidence not recorded.
  - readme: https://github.com/pentaho/mondrian (fetched 2026-08-28T04:03:52.289748+00:00, sha c64f5547575a)
  - homepage: http://mondrian.pentaho.com/ (fetched 2026-08-29T12:33:25.059728+00:00, sha c9d6f6fb3412)
  - site_page: https://mondrian.pentaho.com/documentation (fetched 2026-08-29T12:33:25.068627+00:00, sha 35f022fa7631)
- Data as of 2026-08-30T08:39:29.467469+00:00.