In one of my previous posts, “How to resize InnoDB logs?”, I gave the advice on how to safely change the size of transaction logs. This time, I will explain why doing it may become necessary.
A brief introduction to InnoDB transaction logs
The transaction logs handle REDO logging, which means they keep the record of all recent modifications performed by queries in any InnoDB table. But they are a lot more than just an archive of transactions. The logs play important part in the process of handling writes. When a transaction commits, InnoDB synchronously makes a note of any changes into the log, while updating the actual table files happens asynchronously and may take place much later. Each log entry is assigned a Log Sequence Number – an incremental value that always uniquely identifies a change.