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Day: November 12, 2024

Describing R Models with Tilde (~)

Steven Sanderson describes a relationship:

The tilde operator (~) in R is more than just a symbol – it’s a powerful tool that forms the backbone of statistical modeling and formula creation. Whether you’re performing regression analysis, creating statistical models, or working with data visualization, understanding the tilde operator is crucial for effective R programming.

Read on to see how it works and several examples along the way.

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The Concepts of Data Control Language in SQL

Joe Celko talks about the lesser-known language in SQL (compared to DML and DDL):

But the truth is that the most important sub-language is the one that needs fixing. You wonder why a three-legged stool works? All three legs have to be coordinated together; the same principle holds an SQL schema.

The third sub language in SQL is the DCL (data control language). This is where you get those database privileges I just mentioned. SQL classes don’t spend a lot of time on DCL for several reasons. The first of all is that you’re a mere USER and you’re probably not allowed to pass out privileges. The original ANSI/ISO security model was pretty simple. The universe was divided into USER and USER. An important concept in that you do not create a privilege, but the ADMIN grants it to a user and it is separate from the DDL.

Click through to learn more.

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The Value of Sufficiency

Rob Farley is good enough:

The French philosopher Montesquieu wrote, “Le mieux est le mortel ennemi du bien, which means, “The best is the mortal enemy of the good.” Montesquieu was an interesting man who lived in the 18th century, and influenced many of the political structures around the world. His book “The Spirit of Law” from 1748 described ways to avoid absolute power, established concepts like “innocent until proven guilty”, and campaigned against slavery. I guess some countries adopted those ideas more than others.

I mentioned it because Josephine Bush has invited us to write about the topic of “Good enough is perfect“. And while I realise that the two statements are not identical, I consider that they are essentially the same. If we always strive for perfect then we can all too easily miss the mark of being able to deliver anything worthwhile. As a consultant I have to understand that the ideal solution for my customers is not the one where everything is completely perfect if achieving that means that the cost is too high. Instead, I need to find the point where good enough really is good enough.

Understanding value at the margin is a vital skill.

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Execute a Collection of Child Pipelines from Metadata in Data Factory

Andy Leonard continues a series on design patterns:

In this post, I clone and modify the dynamic parent pipeline from the previous post to retrieve metadata from an Azure SQL database table for several child pipelines, and then call each child pipeline from a parent pipeline.

When we’re done, this pipeline will:

  1. Read pipeline metadata from a table in an Azure SQL database
  2. Store some of the metadata (a collection of pipelineID values) in the (existing) pipelineIdArray variable
  3. Iterate the pipelineIdArray variable’s collection of pipelineID values
  4. Execute each child pipeline represented by each pipelineID value stored in the pipelineIdArray variable

Read on to learn how.

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