#performance articles and events

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Replication Lag is just a fact of life with async-replication. We can’t stop lag, but we can help to reduce it. Many times the Seconds_Behind_Source can be very deciving, I have seen it go from 1 hour...

Usually one would expect that ALTER TABLE with ALGORITHM=COPY will be slower than the default ALGORITHM=INPLACE. In this blog post we describe the case when this is not so....

The thing I wish I’d learned while still a DBA is how to use perf. Conversely after moving to a developer role, getting access to real external client workloads to get a perf recording directly is rar...

Late one evening, I was staring at one of our large MySQL installations and noticed the database was hovering around 7-10 run queue length (48 cores, ~500 gigs memory, fusionIO cards). I had been scra...

Sometimes, the MySQL Optimizer chooses a wrong plan, and a query that should execute in less than 0.1 second ends-up running for 12 minutes!This is not a new problem: bugs about this can be traced bac...