String interning and beyond, in differential dataflow

Frank McSherry (@frankmcsherry), 10 December 2018

Differential dataflow does a great number of interesting bits of data processing, but what about when you want to use complicated types, like strings? In this post we’ll check out how to use differential dataflow to intern strings, replacing them with integer identifiers that will allow the rest of our computation to execute more efficiently. From there, we’ll see how this generalizes to automatically assigning distinct record identifiers to collection elements, much like a database does!

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Physical Adressing on Real Hardware in Isabelle/HOL

Lukas Humbel (home), 09 November 2018

Modern memory systems are much more complicated than the traditionally assumed virtual and physical address space separation. We explain in this post which effects can not solely expressed by the basic model and are important for correct function of operating systems. We summarize our recent paper. In this work we present a theory for addressing in such modern memory subsystems. We formalize the theory in Isabelle/HOL.

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A hammer you can only hold by the handle

Andrea Lattuada (@utaal), 05 November 2018

Today we’re looking at the rust borrow checker from a different perspective. As you may know, the borrow checker is designed to safely handle memory allocation and ownership, preventing accessess to invalid memory and ensuring data-race freedom. This is a form of resource management: the borrow checker is tracking who’s in charge of a chunk of memory, and who is currently allowed to read or write to it. In this post, we’ll see how these facilities can be used to enforce higher-level API constraints in your libraries and software. Once you’re familiar with these techniques, we’ll cover how the same principles apply to advanced memory management and handling of other more abstract resources.

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