I have some experience as a sysadmin, but I have never dealt with databases. Though I am familiar with the theory of relational databases and can create complex databases in Access, I lack any knowledge on working with other databases like MySQL, PostreSQL, Oracle, etc. It is typically the role of a database administrator to handle such databases.



Unfortunately, my lack of experience with MySQL has caused me to miss out on several good job opportunities in the past. Can you suggest any reading materials or resources that can help me gain knowledge in this area?

There are a plethora of resources out there to help you learn and master MySQL as well as other database systems. Here are some you might find useful:

Books:

"MySQL Crash Course" by Ben Forta
"High Performance MySQL: Optimization, Backups, and Replication" by Baron Schwartz.
"MySQL (5th Edition) (Developer's Library)" by Paul DuBois.
Online Courses:

"The Ultimate MySQL Bootcamp: Go from SQL Beginner to Expert" by Colt Steele available on Udemy.
"SQL - MySQL for Data Analytics and Business Intelligence" also on Udemy.
"Introduction to Databases and SQL Querying" on Udemy.
"MySQL, SQL and Stored Procedures from Beginner to Advanced" on Udemy.
"MySQL Databases With Python Tutorial" on Udemy.
"Learn SQL Basics for Data Science" on Coursera by University of California, Davis
Websites/Tutorials:

MySQL website itself has good dоcumentation and is a good starting point: MySQL 8.0 Reference Manual
W3Schools has great, interactive SQL tutorials which are easy to follow and understand.
SQLZoo is a hands-on interactive SQL tutorial.
The SQLJOIN Tutorial Page is a useful resource for understanding JOIN queries in SQL.
Khan Academy's course on SQL is another good online resource.
Interactive Learning Platforms:

LeetCode has a database section where you can solve problems and learn with hands-on practice.
HackerRank also offers SQL challenges to solve.
StrataScratch provides SQL exercises that are sourced from real companies.
Remember, the best way to learn is to practice. Once you go through some of these resources, try to build your own projects or replicate existing ones. You can also contribute to open source projects or solve practical problems on websites like LeetCode and HackerRank.


Here are additional resources you might find helpful:

Books:

"Learning MySQL: Get a Handle on Your Data" by Hugh E. Williams and Saied Tahaghoghi.
"MySQL Explained: Your Step By Step Guide" by Andrew Comeau.
"MySQL Cookbook: Solutions for Database Developers and Administrators" by Paul DuBois.
Online Courses:

"MySQL for Data Analysis - SQL Database for Beginners" on Udemy.
"SQL & Database Design A-Z™: Learn MS SQL Server + PostgreSQL" on Udemy.
"Introduction to Structured Query Language (SQL)" on Coursera by University of Michigan.
Tutorials and Articles:

Tutorialspoint MySQL Tutorial: A well-rounded selection of basic to advanced MySQL tutorials.
A Gentle Introduction to SQL Using MySQL: Another great tutorial from SQLZoo, this time specifically for MySQL.
GeeksForGeeks MySQL: A collection of MySQL articles and tutorials to explore different features.
Interactive Learning Platforms:

Mode Analytics: An interactive tutorial that also provides a free, private, in-browser SQL environment to practice.
SQLBolt: Provides a set of interactive lessons and exercises designed to help you quickly learn SQL right in your browser.
DataCamp: Offers a course "Intro to SQL for Data Science".
Lastly, if you want a more hands-on approach, you can also install MySQL on your own machine and experiment with it. There's plenty of data available online for you to play with. The most common are Northwind and Sakila databases which are provided by Microsoft and MySQL respectively.


Few more resources worth considering:

Books:

"MySQL Troubleshooting: What To Do When Queries Don't Work" by Sveta Smirnova.
"Murach's MySQL (3rd Edition)" by Joel Murach.
"Effective MySQL: Optimizing SQL Statements" by Ronald Bradford.
Online Courses:

"SQL & MySQL for Beginners: Analyse and Manipulate Data" on Udemy.
"The Complete MySQL Developer Course" on Udemy.
"MySQL Database Development for Beginners" on Udemy.
"SQL for Data Science" on Coursera by University of California, Davis.
"Managing Big Data with MySQL" on Coursera by Duke University.
Tutorials and Articles:
MySQL Tutorial: Comprehensive range of tutorials from basics to advanced topics.
JavaTpoint MySQL Tutorial: Wide collection of MySQL tutorials suitable for people of all levels.
MySQL Data Types: Detailed explanation of MySQL Data Types.
Interactive Learning Platforms:
Sololearn SQL tutorial: A mobile-centric platform for learning SQL. You can learn conveniently on the go.
edabit: SQL challenges based on difficulty to help you learn at your own pace.
Remember to take advantage of these resources by not only consuming the content, but also actively doing the exercises, projects, or challenge problems they provide. This will help you to better grasp the concept and provide practical experience, making you feel more comfortable and confident with MySQL.

Also, joining SQL or database-related communities on platforms like Stack Overflow, Reddit or GitHub can be incredibly beneficial. They can provide a wealth of knowledge, new perspectives, and real-world problems to practice with. Plus, having a community to rely on when you run into problems can be a significant help.

For the past six months, I've been working on PostgreSQL DBA, but I recently transitioned from being a Linux admin with a broad range of responsibilities. Here's how I became a DBA:

1. In my previous role, I had extensive experience with PostgreSQL, handling tasks such as administration, replication, load balancing, pooling, backups, and on-the-fly migrations between major versions. Dealing with various situations allowed me to gain valuable experience.
2. Additionally, I delved into the inner workings of Linux and its kernel, thanks to Gentoo. I studied topics like memory management, processes, and more. The book "Linux Kernel" by Bovet and Cesatti proved to be an invaluable resource.
3. Another crucial aspect was gaining experience in performance analysis, inspired by Brendan Gregg's work. This skill becomes especially important when there is a lack of monitoring tools, and immediate identification of performance bottlenecks is required.
4. Building connections on LinkedIn, engaging in direct communication with professionals, attending conferences, and subscribing to specialized blogs/RSS feeds (such as PostgreSQL Planet and Postgres) has been instrumental in expanding my knowledge and networking within the PostgreSQL community.
5. Regarding PostgreSQL itself, I would highly recommend the following books: "PostgreSQL 9 Administration Cookbook" by S. Riggs and H. Krosing (PACKT, 2010), "PostgreSQL Replication" by Z. Boszormenyi and H. J. Schonig (PACKT), and "PostgreSQL 9.0 High Performance" by G. Smith (PACKT).

In summary, my journey to becoming a DBA involved hands-on experience with PostgreSQL, a deep understanding of Linux internals, proficiency in performance analysis, active networking, and continuous learning through reputable resources.

I have been working as a system administrator, primarily focusing on Oracle, for over 10 years. Understanding Unix-like systems at least at the user level is essential. This includes the ability to configure a system without graphical interfaces and having a deep understanding of its inner workings, such as memory allocation and the IO system. I have experience with RHEL, Solaris, and HP-UX systems.

Among all the Oracle courses I have taken, the "SQL & PL SQL Fundamentals" provided me with the most insightful knowledge. Although I initially listened to it back in the 8i era, I highly recommend starting with this course. On the other hand, the "Database Administration" courses were not as useful to me, possibly due to the timing of when I took them.

Once you have grasped the basics of SQL, it is crucial to delve into memory allocation. While Oracle 11g has some built-in capabilities, understanding this process is still necessary. Additionally, studying backup and recovery is a must. Finally, if you work as a database administrator, it's crucial to focus on disaster recovery and performance tuning. These topics are frequently encountered and don't have standardized solutions.