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Day: April 28, 2026

Support for Typst in knitr

Published 2026-04-28 by Kevin Feasel

Yihui Xie makes an announcement:

A few weeks ago I added preliminary support for Typst to knitr. The way it works is simple: if your file has the extension .Rtyp, knitr will recognize it as a Typst document, knit it, and produce a .typ output file. The chunk syntax follows the same Markdown-style fenced code block convention: ```{r} to start a chunk and ``` to end it, with inline R expressions written as `r expr`. A minimal example (hello.Rtyp):

Click through for that example, as well as some notes on Typst and HTML.

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Tips for Using Bar Charts

Published 2026-04-28 by Kevin Feasel

Ruben Van de Voorde shares some tips:

The bar chart is one of the oldest statistical graphics we have. William Playfair published the first bar chart for categorical comparison in 1786: a horizontal bar chart of Scotland’s imports and exports with trading partners. Two and a half centuries later, it’s a familiar sight wherever numbers are shown visually: news stories, research reports, business dashboards; bar charts are everywhere. Most people have seen one before and instinctively know how to read them.

Click through for plenty of examples of where bar charts work best, as well as important notes when using them. I’m particularly fond of Cleveland dot plots versus bar charts, but a good bar chart does tell an important story.

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Unmaterialized Columns in Power BI

Published 2026-04-28 by Kevin Feasel

Teo Lachev has ideal columns:

Coming back from a long vacation, I’ve almost missed this interesting Power BI enhancement: Power BI unmaterialized calculated columns. Normally, I avoid the traditional DAX calculated columns for a variety of reasons, such as confusion about where business logic is applied, limited support across storage modes (for example, Direct Lake doesn’t support them), longer refresh times, etc. This not to say that calculated columns can’t be useful, such as in the case where you need to flatten a parent-child hierarchy. But unmaterialized calculated columns could open interesting scenarios that go beyond content translation to other languages mentioned by Microsoft in the April 2026 update.

Click through to learn what unmaterialized columns are and how they work.

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Time Delay for Online Checksums in PostgreSQL

Published 2026-04-28 by Kevin Feasel

Cristophe Pettus notes an upcoming change to PostgreSQL 19:

For about fifteen years the answer to “can I turn on data checksums without an initdb?” has been “not really.” pg_checksums showed up in PostgreSQL 12 and made the job survivable, but you still had to shut the cluster down. For anyone running 24×7 production, that has left the same three options: take the downtime, fail over through a checksummed replica, or live without checksums.

PostgreSQL 19 adds a fourth path. A commit from Daniel Gustafsson on April 3rd wires up online enabling and disabling of data checksums: the command completes immediately, and the cluster keeps serving traffic while a background process rewrites every heap and index page in the cluster to carry (or drop) the checksum.

Read on to see what it will do, as well as the consequences.

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Storage Load Testing SQL Server

Published 2026-04-28 by Kevin Feasel

Anthony Nocentino designs a test:

I’ve been doing storage load tests for SQL Server for a long time, both as a consultant and now in my work at Everpure, and I see the same patterns over and over. Someone spins up a VM with two vCPUs, points it at a storage subsystem (cloud or on-prem), runs a thousand threads at it, and then concludes that the storage stinks. Or the opposite, where they buy a 64 gigabit HBA, plug it into the wrong PCIe slot, and wonder why they’re leaving half of the capacity on the table.

Designing a good load test isn’t about pushing the biggest number you can find. It’s about knowing what your gear is supposed to do, driving load until you find the point where the system breaks down, and measuring at the right places along the way. In this post, I’m going to walk you through how I think about designing a storage load test, the tools I reach for, and the pitfalls that will invalidate your results if you’re not paying attention.

Click through for Anthony’s thought process.

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