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Day: April 30, 2021

Plotting XGBoost Trees with R

Andrew Treadway shows off a method to visualize the results of training an XGBoost model:

In this post, we’re going to cover how to plot XGBoost trees in R. XGBoost is a very popular machine learning algorithm, which is frequently used in Kaggle competitions and has many practical use cases.

Let’s start by loading the packages we’ll need. Note that plotting XGBoost trees requires the DiagrammeR package to be installed, so even if you have xgboost installed already, you’ll need to make sure you have DiagrammeR also.

Click through for the process. H/T R-Bloggers.

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Validating IP Addresses using Powershell

Joey D’Antoni needs a good IP address:

I had a client ask me to write a PowerShell script (for an Azure Automation runbook) to automate the creation of firewall rules for an Azure SQL Database. As part of this process, I was planning on having to validate the IP addresses (a valid IP address is of the format x.x.x.x where x is an integer between 0 and 255) by having to write some code to split the IP address string into individual octets and figuring out if each value was a valid number. However, in doing research (searching Stack Overflow), I discovered PowerShell has a built-in IP address data type, which made my life way easier.

Read on to see how you can use this to your advantage.

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Just Take My Money: Paying for Power BI Premium per User

Wolfgang Strasser shows how hard it can be to let someone take your money in return for goods or services:

Initially I told my customers, purchase the PPU license in the Microsoft 365 portal and thought that it should be an easy deal.. but hey – it’s licensing, Microsoft licensing involved…

The place where to buy the PPU add-on is not that obvious as it looks like.

Read on to learn how to upgrade to Premium per User if you already have a Professional license.

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User-Defined Roles in SQL Server

Greg Larsen shows us how to create and use user-defined security roles in SQL Server:

When developing an application that accesses SQL Server, you need to set up a security model, so each user gets the access they need based on their job duties. Some applications require the same access for all users, while other application might require different security access rights based on the role a user has in the organization. The best practice for providing user access is to use role-based security. SQL Server provides user-defined Server and Database roles for defining security rules for different user security needs. This article will discuss how to use user-defined server and database roles to provide secure access to SQL Server resources.

This is something I think DBAs tend to under-utilize. Granted, a big part of why I think DBAs under-utilize it is that we often have Windows groups that we can use as the base for roles, but even so, it’s a good way to secure assets in the database.

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Working with High Virtual Log Files

Chad Callihan explains the notion of Virtual Log Files and has a process to handle them when they multiply like rabbits:

Today, I want to go over what Virtual Log Files are and how to handle them if you have too many in your databases.

A SQL Server log file is made up of smaller files called Virtual Log Files (VLFs). As the log file grows, so will the count of VLFs. I haven’t seen or heard of a calculation that can be worked out to determine how many VLFs you should have or how many is too many for a database. I’ve heard that you shouldn’t have more than a few hundred. I’ve also heard to not worry about VLFs until you break 1000. If you check your databases and have thousands in a database, I would say it’s best to get that count lowered whether you’re seeing issues yet or not.

Read on to see how.

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