SQL vs NoSQL: How to Choose the Right Database
The choice isn't about which database is modern or fast. It's about the shape of your data and how you'll query it. A practical comparison and a simple decision process.
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Tips & writing
Notes from the workbench
Practical engineering tips, design theory and performance breakdowns — written for developers and founders who like their advice tested in production.
Filtering by tag #sql — clear
SQL Joins Explained with Simple Examples
INNER, LEFT, RIGHT and FULL joins, the anti-join trick for "find rows with no match", and why joins sometimes multiply your rows. Clear examples you can run against any SQL database.
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Why LOWER() and TRIM() Kill Your SQL Index Performance
A query that runs in 4ms locally but takes 9 seconds in production usually has the same cause: a function like LOWER() or TRIM() wrapped around an indexed column. Learn why this makes queries non-sargable, how to spot it in your execution plan, and five engine-specific fixes — from functional indexes to PostgreSQL's citext type.
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The N+1 Query Problem: How to Spot It and Fix It for Good
Your page loads 20 posts and quietly runs 21 database queries. The N+1 problem is the most common ORM performance bug. Here is how to recognise it and fix it in any stack.
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Database Indexing Explained for Application Developers
One missing index can turn a 5ms query into a 5 second one. What indexes are, how to read EXPLAIN, how composite indexes really work, and when an index makes things worse.
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