WinJoe, Was ist Delta Format?

Delta format (often called Delta Lake) is an open-source data storage layer originally developed by Databricks. 

It sits on top of Apache Parquet and enhances it with database‑like guarantees and metadata management. 

Delta is designed specifically for large-scale data engineering where reliability, consistency, and performance are essential - according to the creators, Databricks,

Big Data's New Vacation Home - The Lakehouse; Microsoft's Approach

The lakehouse concept combines the capabilities of data lakes (which have scalability qualities) and data warehouses (which have advanced query functionality).

Microsoft Fabric's resources on Data Engineering delves into the concept of data lakehouse (and Microsoft's SaaS implementation, OneLake, billed as OneDrive for data)  with notes on how the lakehouse makes use of Apache Spark.

Troubleshooting WSL2 Memory Hogging

WSL2 hogs memory and doesn't release it even when all consoles are closed. Do wsl --shutdown to free up memory.

Why does TypeScript feel a bit C-Sharpy?

TypeScript was created by Anders Hejlsberg, a Danish software engineer, in 2012. He formerly created C# around the year 2000. He is also known for Turbo Pascal and Delphi, both extraordinary products in their time. Deservedly he is a Microsoft Technical Fellow (a list of whom appear here).

Types in TypeScript

The basic types are called primitives: 

• boolean
• number (which represents integers and floating points)
• string  

There is also:

•  BigInt (ES2020+) to represent whole numbers larger than 2^53 -1, and
•  symbol to create unique identifiers

Starting with ES2015, symbol is a primitive type, whose values are created by calling the Symbol constructor.

Examples:

let sym1 = Symbol();

let sym2 = Symbol("keyname");

Symbols are immutable and unique, which can result in what may be initially feel like strange behaviour, but on reflection makes sense.

let sym2 = Symbol("key");

let sym3 = Symbol("key");

sym2 === sym3; // triple equality - false, Symbols are unique.

Node Version Manager - Strongly Recommended

The Node version manager, nvm, is strongly recommended to manage your version of Node.js and npm. 

It also allows switching between various versions of Node (Nodejs and npm) for testing purposes. 

As per official docs, nvm is designed to be installed per-user and invoked per-shell. It works on "any POSIX compliant shell" - including on Unix, macOS and WSL.

Once you install nvm (by wget'ing the installation shell script and piping it to bash) you can restart WSL and start using nvm.

Some nvm commands to know:

nvm install node   # install latest version

nvm install --lts     # install latest LTS version

nvm use node        # switches to latest version

nvm use <version>    #switch to a specific version

To see all Node versions, do nvm ls.   Node uses semantic versioning, following the pattern MAJOR.MINOR.PATCH.

nvm ls shows the version active in shell in blue, and installed versions in green. Yellow are versions referenced by aliases but not installed.

Installing a Transpiler

Do install a transpiler in WSL as follows.

sudo npm install -g typescript

The -g option to npm install is short for --global and means install the said package globally (global npm directory) as opposed to the local node_modules folder of a project.

Binaries are then also exposed on your PATH, so you can run tsc conveniently.

Note that you need an up-to-date installation of Node to run TypeScript. If not, some of the modern operators (e.g. null coalescing operator) will not work when running tsc.