[MariaDB discuss] Re: Adding an index to a large table

On Sat, 22 Mar 2025, 20:02 edi mari, <edim2525@gmail.com> wrote:

Thanks Gordan. This is a cluster and I have slaves. How does the ALGORITHM=INPLACE, LOCK=NONE; configuration impact the slaves ?

The slaves will start the ALTER when it gets in the binlog - which will happen when ALTER completes. So if it takes an hour for that ALTER to complete, your slaves will get a 1 hour lag spike that won't start to clear until they finish executing the ALTER they replicated down.