Women in Open Source & Presto – Getting started in the Presto open source ecosystem

Women in Open Source & Presto – Getting started in the Presto open source ecosystem

Women in Open Source & Presto – Getting Started in the Presto Open Source Ecosystem – Neha Pawar, Startree; Rebecca Schlussel, Meta; RongRong Zhong, Celonis & Moderated By Dipti Borkar, Microsoft Among GitHub users with at least ten contributions, a mere 6% were women. This is way less than the ratio of women in tech that various research shows at 26%. Given the amount of investment going into and the growth / success of companies based on open source as well as the enormous demand for developers in open source, it is a ratio we need to strive to improve for women. In this panel, we will discuss a few areas: – The journey of each panelist into open source projects – The benefits they have seen by participating in open source projects particularly Presto – The challenges women face in male-dominated open source communities – Ideas, suggestions and guidance to budding engineers on getting started with open source including 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.