Fireside Chat: Journey to Innovation: Unleashing the Power of Open Source Through Open Governance

Fireside Chat: Journey to Innovation: Unleashing the Power of Open Source Through Open Governance

The Presto Foundation is the organization that oversees the development of the Presto open source project. Hosted at the Linux Foundation, the Presto Foundation operates under a community governance model with representation from all its members. In this fireside chat, we’ll hear more from Girish Baliga, Chair of the Presto Foundation, on what it actually means to be a Presto Foundation member and why this governance model is so important for open source projects. We’ll also talk with Vikram Murali of IBM, the newest member of the Presto Foundation. He’ll share more about IBM’s journey to Presto, how they’re using it in IBM’s new watsonx.data lakehouse, and why the Presto Foundation played an important role in IBM’s decision to choose Presto.

Common Sub Expression Optimization at Facebook

Common Sub Expression Optimization at Facebook

In complex analytics queries, we often see repeated expressions, for example parsing the same JSON column but extracting different fields, elaborate CASE statement with common predicates and different ones. Previously, Presto will compute the same expression many times as they appear in query. With common sub expression optimization, we would only evaluate the same expression once within the same project operator or filter operator. In our workload, we’ve seen 3x improvements on certain queries with expensive common sub expressions like JSON_PARSE. Microbenchmark also shows a consistent ~10% performance improvement for simple common sub-expressions like x + y. In this talk, we will talk about how this is implemented.