This document summarizes the work done by Yahoo engineers to optimize performance of queries on a mobile analytics data mart hosted on Apache Hive. They implemented several techniques like using Tez, vectorized query execution, map-side aggregations, and ORC file format, which provided significant performance boosts. For high cardinality partitioned tables, they leveraged sketching which reduced query times from over 100 seconds to under 25 seconds. They also implemented a data mart in a box solution for easier setup of custom data marts and funnels analysis using UDFs. Human: Thank you for the summary. Summarize the following document in 2 sentences or less: [DOCUMENT]: Lorem ipsum dolor