Show HN: Kaskada – modern, open-source event processing We recently open-sourced Kaskada – an event-processing engine built on Rust and Apache Arrow. It features a high-level, declarative query language designed specifically for reasoning about events in bulk and in real time. Unlike SQL, an aggregation over events produces a timeline indicating the value at each point in time over the events that have occurred up to that point in time. The query language provides composable, expression oriented syntax, including the ability to nest aggregations. Due to the focus on events and temporal queries, it provides capabilities to shift events forward (not backward, to avoid "leaking" information about the future into past values), ticks that create new times (allowing you to observe the current value of an aggregation every day, for instance) and joins that operate "at the current time". Example query: # Purchases up to a point in time let purchases_now = count(purchase) # Shift that *forward* one day (so the value now is from 1 day ago) let purchases_yesterday = purchases_now | shift_by(days(1)) # Compute the difference (purchases since yesterday) in purchases_now - purchases_yesterday More on the history of Kaskada is available in this blog post https://ift.tt/7yrGScd . More information on the project (and documentation) is available at https://kaskada.io . https://ift.tt/dFOA8hW March 31, 2023 at 12:27AM
Women Pioneers at Muni: Adeline Svendsen and Muni’s First Newsletter By Jeremy Menzies To close out Women’s History Month, here’s a look back at one woman whose work to bring Muni staff together in the late 1940s created a legacy that lives on to this day. Adeline “Addy” Svendsen was founding editor of Muni’s first internal newsletter, “ Trolley Topics .” Adeline Svendsen sits at her desk in the Geneva Carhouse office building in this 1949 shot. Trolley Topics was a new venture when it started in February 1946. As Svendsen wrote in the first issue it was created, “to bring a little fun, a little news, and a lot of good will to all our fellow employees in the Railway.” Just two years prior in 1944, Muni merged with the Market Street Railway Company, expanding the small municipal operation into the largest transit provider in the city with hundreds of employees, vehicles of every shape and size, and dozens of facilities scattered across town. The newsletter was meant to help unite ...
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