Sergei Petrunia

Query Optimizer Developer, MariaDB Corporation

Sergei Petrunia is a query optimizer developer at MariaDB Corporation Ab. He implemented MariaDB's optimizer features like Table Elimination (MariaDB 5.1), improvements to semi-join subquery optimizations (MariaDB 5.3/5.5), SHOW EXPLAIN (MariaDB 10.0), and ANALYZE for statements (MariaDB 10.1) Prior to Monty Program, he has worked for MySQL Ab/Sun Microsystems, where he was the author of query optimizer features like Partition Pruning, Index Merge (MySQL 5.1), and numerous smaller improvements in query optimizer and other parts of the server. He maintains a highly technical blog at

Submitted Sessions

The Cassandra Storage Engine allows access to data in a Cassandra cluster from MariaDB. Learn:
* How to make use of it
* When to use it, and if CQL makes sense
* Data & command mapping
* Use cases
* Future plans

And more. This will benefit MySQL users as well, since this is just a storage engine using the storage engine interface.

How can you tell if queries in your application use good query plans? And if they don't, is there any way to force the query optimizer to use a good query plan?

This tutorial aims to give an all-around answer. We will:

show how to find queries which use expensive query plans, discuss possible reasons why the optimizer can make poor query plan choices, show how to determine what... [read more]

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