With this Ruby script you can print all values in a Redis database to your console (derived from this bash...
When you allow file uploads in your app, a user might upload content that hurts other users. Our primary concern...
In Ruby on Rails ActiveRecord::Relation#merge overwrites existing conditions on the same column. This may cause the relation to...
I found the linked article very helpful to refresh my understanding of database indexes. As a small bonus, it includes...
Maintaining larger projects makes it more difficult to balance refactoring and upgrade tasks according to its actual value. Consider to...
Let's say we have posts with an attribute title that is mandatory. Our example feature request is to tag...
Rails Active Support provides some helpful methods for calculating times and dates, like Duration#ago or Duration#from...
In dieser Card machst du einige Übungsaufgaben um Linux Server mit Ansible zu verwalten. Da es vermutlich zu aufwendig ist...
The change_column method for rails migrations support casting with a custom SQL statement. This allows us to change a...
This is a checklist I use to work on issues. For this purpose I extracted several cards related to the...
In the past we validate and set default values for boolean attributes in Rails and not the database itself.
Since Rails 7 you are able to encrypt database information with Active Record. Using Active Record Encryption will store an...
To retrieve only unique combinations of the selected attributes: You can omit rows, where all selected columns are equal with...
Das Standardtool für Monitoring auf AWS ist Cloudwatch. Du hast dir in den AWS Kapiteln Cloudwatch sicherlich schon grundsätzlich angesehen...
Mit SQL spricht man mit relationalen Datenbanken. Ziele Verstehe die folgenden SQL Befehle SELECT WHERE ORDER INNER JOIN, LEFT JOIN...
Du musst kein Netzwerkspezialist sein oder iptables in- und auswendig kennen. Du solltest aber die Grundlagen verstanden haben. Spätestens wenn...
Using ActiveRecord's #signed_id and .find_signed methods you can create URLs that expire after some time. No conditionals...
When an object is created / updated, various callbacks are executed in this order: before_validation after_validation before_save
To delete a specific redis-DB you need to use the FLUSHDB-command in combination with the SELECT-command. For...
In dieser Card geht es um Netzwerke in Kubernetes. Schau noch einmal kurz auf Netzwerke zurück und schau dir die...
TLDR if you define a equality method for a class you must also implement def hash. Ruby has a lot...
We had a strange behaviour on one of our mariadb-servers: Everyday at around midnight we saw that the root...
When changing glibc versions, it's possible to end up with corrupt indexes in PostgreSQL. Are My Indexes Affected?
When changing the glibc version, it's possible that the upgrade also includes changes to how locales work.