MySQL Replication Lag, How to Diagnose
Replication lag means the replica database is falling behind the source, applying changes later than they actually happened — diagnosing it correctly means...
Category
MySQL
Fixes for connection limits, query performance, and encoding issues in MySQL.
MySQL Character Encoding Showing Question Marks
Question marks (or garbled characters like ’) appearing instead of accented letters, emoji, or other special characters almost always means there's a...
MySQL Deadlock Found When Trying to Get Lock
A deadlock in MySQL happens when two transactions each hold a lock the other one needs, and neither can proceed — MySQL detects this automatically and kills...
MySQL Slow Query Despite Having an Index
Having an index on a column doesn't guarantee MySQL will actually use it efficiently, or that using it will make a query fast — the query optimizer makes...
MySQL "Table Doesn't Exist" After Migration
Getting a "table doesn't exist" error right after running a migration that supposedly created that exact table almost always means the migration either didn't...
MySQL "Too Many Connections" Error Fix
The "too many connections" error in MySQL means the server has hit its configured connection ceiling and is refusing new clients. Like most databases, this is...