columnar-database
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Jethro
Jethro (JethroData) is an enterprise software company that makes interactive business intelligence run fast on big data. Its index-based SQL engine sits between BI tools like Tableau, Qlik and MicroStrategy and data stored in Hadoop or Amazon S3, using full indexing, auto-cubes and result caching to return queries in seconds across tens of billions of rows and thousands of concurrent users - at Hadoop-scale cost and without manual data engineering.
Aaron Katz
Aaron Katz is the Co-Founder and CEO of ClickHouse, the world's fastest OLAP database company, which he has built from a 12-person open-source project into a $15 billion enterprise serving 4,000 customers including Tesla, Anthropic, Meta, and OpenAI. A veteran of Salesforce (12 years, from $20M to $4B in revenue) and Elastic (CRO, $5M to $500M), Katz assembled a founding team mid-pandemic, relocated engineers from Russia to Amsterdam, and raised over $1 billion in funding. In January 2026 ClickHouse closed a $400M Series D; by May 2026 the company surpassed $250M ARR, growing 250% year-over-year.