I am just starting my journey into database management and keep coming across the terms RDBMS and CRUD. Could someone explain in simple terms what a Relational Database Management System is and how it differs from a standard flat file? Also, I would love to see a few examples of popular RDBMS used in the industry today. Finally, what does the acronym CRUD stand for in the context of database operations? I want to make sure I have the fundamental terminology down before I start learning SQL.
3 answers
An RDBMS (Relational Database Management System) is a program that allows you to create, update, and administer a relational database. Unlike a flat file, it organizes data into tables with rows and columns, linked by unique keys. This structure ensures data integrity and reduces redundancy. Popular examples include MySQL, PostgreSQL, Microsoft SQL Server, and Oracle Database. CRUD is an acronym that describes the four basic functions of persistent storage: Create (adding new data), Read (retrieving data), Update (modifying existing data), and Delete (removing data). These operations are the bread and butter of any backend developer or data analyst working with structured data.
That is a great summary of the basics, but in modern web development, do we still strictly follow CRUD for every interaction, or are there scenarios where a database might only allow 'Read' and 'Create' operations, like in an append-only ledger? I am curious how these rules change for high-security environments.
Think of an RDBMS like an Excel workbook where different sheets are linked together by IDs. CRUD is simply the four things you can do to the data within those sheets
I agree with Lisa; the Excel analogy is perfect for beginners. I’d just add that while Excel is great for small sets, an RDBMS like PostgreSQL can handle millions of rows with much higher efficiency and security through SQL queries.
Brandon, you are touching on "Immutable Databases" or "Event Sourcing." In those cases, you technically skip the 'Update' and 'Delete' parts of CRUD to maintain a perfect audit trail. However, for 95% of standard applications like e-commerce or CRM systems, the full CRUD cycle is still the gold standard. In high-security domains like Cyber Security or Fintech, 'Delete' is often replaced by a 'Soft Delete' where a flag is toggled, but the record stays in the RDBMS for compliance.