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Day: June 2, 2023

A Primer on Regular Expressions

Published 2023-06-02 by Kevin Feasel

Steven Sanderson provides a quick guide to regular expressions:

Regular expressions, often abbreviated as regex, are powerful tools used in programming to match and manipulate text patterns. While they might seem intimidating at first, regular expressions are incredibly useful for tasks like data validation, text parsing, and pattern matching. In this blog post, we’ll explore regular expressions in the context of R programming, breaking down the concepts step by step and providing practical examples along the way. By the end, you’ll have a solid understanding of regular expressions and be ready to apply them to your own projects.

This is an extremely powerful language which can take years (decades?) to master, especially considering that there are several regular expression syntaxes and they don’t all behave the same way. But still, I’ve found that the more familiar you are with regular expressions, the simpler certain classes of problem become.

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PyPI and Malicious Code

Published 2023-06-02 by Kevin Feasel

Steven Vaughan-Nichols gives us the story:

The Python Package Index (PyPI), is the most popular Python programming language software repository. It’s also a mess. Earlier this year, the FortiGuard team discovered zero-day malware in three PyPI packages called “colorslib,” “httpslib,” and “libhttps.”  Before that, 2022 closed with  PyTorch-nightly on Linux being poisoned with a fake dependency. More recently, PyPI had to stop new user registrations and project creations because of a flood of malicious users. PyPI isn’t the only one to notice the user trouble. The Python Software Foundation (PSF) received three subpoenas for PyPI user data. What is going on here!?

Read on to learn more about what’s happening with the most popular Python repository.

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SQL Anti-Patterns Extended Event in SQL Server 2022

Published 2023-06-02 by Kevin Feasel

Dennes Torres finds some anti-patterns:

One of the new Extended Event available in SQL Server 2022 is the query_antipattern. This extended event allows to identify anti-patterns on the SQL queries sent to the server.  An anti-pattern in this case is some code that the SQL Server optimizer can’t do a great job optimizing the code (but cannot correct the issue automatically).

This is a very interesting possibility: Including this event in a session allow us to identify potential problems in applications. We can do this in development environments to the the problems earlier in the SDLC (Software Development Life Cycle).  Let’s replicate some examples and check how this works.

Dennes shows two examples and notes that there are five total listed in the Extended Event, but that the documentation is a bit lacking to explain their intent.

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Showing KQL Queries

Published 2023-06-02 by Kevin Feasel

Dany Hoter looks at some KQL query plans:

Each visual on the page is going to summarize data from one or more queries and add the summarize part of the query.

If your model contains multiple tables in direct query with relations between them, the connector will generate joins between the tables.

Selecting values in filters will create multiple where conditions.

In order to see the final query and understand the performance implications of each query and the total query load created by a report, you need to use the command “.show queries” in the context of the database.

Click through for Dany’s notes on the topic, including a few tips on what to look for.

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