Time Travel for Iceberg Tables in Presto

Introduction Presto, an open-source distributed SQL query engine, excels at querying large data sets distributed across diverse data sources. It has maintained its position as a high-performance data analytics tool for over a decade. As data collection capabilities expand, businesses increasingly recognize the importance of historical data alongside current data. With the recent release of…

Even Faster Unnest

Unnest is a common operation in Facebook’s daily Presto workload. It converts an ARRAY, MAP, or ROW into a flat relation. Its original implementation used deep copy all the time and was very inefficient. In Unnest Operator Performance Enhancement with Dictionary Blocks, the author improved the Unnest operator by up to 10x in CPU and…