MySQL
6 posts in this category
MySQL Isolation Levels: Common Race Conditions and How to Fix Them
MySQL's default REPEATABLE READ doesn't prevent every race condition. Dirty reads, lost updates, phantom reads, write skew — which isolation level prevents which, when SELECT FOR UPDATE is the real fix, and when optimistic locking is better.
MySQL Deadlock: How to Read InnoDB Logs and Reduce Occurrence
MySQL auto-resolves deadlocks but randomly rolls back a transaction, causing errors at the app layer. How to read SHOW ENGINE INNODB STATUS to find exactly which row was locked, common causes, and 5 ways to reduce deadlock probability.
Can SQL handle large datasets? Indexes and query design in MySQL
Why SQL still works well at scale when schema, indexes, and query design are correct, from filtering before joins to MySQL patterns for millions of customers.
MySQL ORDER BY + LIMIT Slow Despite Index: Filesort, Composite Index, and Cursor Pagination
ORDER BY combined with LIMIT can trigger a filesort over millions of rows even with indexes in place. How MySQL picks its execution plan, how to read EXPLAIN, and 4 practical optimization patterns.
The role of indexes and the query patterns that make MySQL slow
Why indexes matter in MySQL, and common slow-query patterns such as missing indexes, selecting too much data, or filtering in application code.
Optimizing a MySQL query on 300k+ records
Case study: bringing a MySQL query from 12 seconds down to 200ms using EXPLAIN, composite indexes, and a query rewrite.