Sergei Golubchik

Imagine, you're given a time machine. A fairly limited one, it cannot transport you anywhere. Still, it can show you the past, what your tables looked like at any given point in time. This is exactly what the SQL:2011 standard and MariaDB 10.3+ are giving you. System versioned tables allow you to rewind time and see their content as it was in the past — all using normal SELECT statements. This talk will show how to create system versioned tables, how to use them and how not to kill the performance when doing that. It will present various new applications and use cases that became possible now. Having a time machine, what will you use it for?

Imagine, you're given a time machine. A fairly limited one, it cannot transport you anywhere. Still, it can show you the past, what your tables looked like at any given point in time. This is exactly what the SQL:2011 standard and MariaDB 10.3+ are giving you. System versioned tables allow you to rewind time and see their content as it was in the past — all using normal SELECT statements. This talk will show how to create system versioned tables, how to use them and how not to kill the performance when doing that. It will present numerous different applications and use cases that became possible now. Having a time machine, what will you use it for?

In this talk you'll learn what data statistics MariaDB and MySQL can collect, what statements do that, how to tell the optimizer to use it (it won't necessarily do it automatically!) and how it can make your queries many times faster.

When your SQL query reaches the DBMS, it's the optimizer's job to decide how to execute it for you to get the result as fast as possible. To make this decision optimizer can examine the actual table data, but with multi gigabyte and terabyte tables, the only practical solution is to use various data statistics that were collected in advance. The better the statistics and the more precisely it describes the actual data, the faster the plan will be, because the optimizer image of reality will be closer to the actual reality. In this talk you'll learn what data statistics MariaDB and MySQL can collect, what statements do that, how to tell the optimizer to use it (it won't necessarily do it automatically!) and how it can make your queries many times faster. And, of course, when not to use indexes, when up-to-date statistics is enough.

When your SQL query reaches the DBMS, it's the optimizer job to decide how to execute it for you to get the result as fast as possible. To make this decision optimizer can examine the actual table data, but with multi giga- and terabyte tables, the only practical solution is to use various data statistics that was collected in advance. The better the statistics is and the more precisely it describes the actual data, the faster the plan will be, because optimizer image of the reality will be closer to the actual reality.

In this talk you'll learn what data statistics MariaDB and MySQL can collect, what statements do that, how to tell the optimizer to use it (it won't necessarily do it automatically!) and how it can make your queries many times faster.

And, of course, when not to use indexes, when up-to-date statistics is enough.

We've been writing SQL queries with WHERE, GROUP BY, ORDER BY, HAVING for decades. But nobody is using DOS 3.2 or Windows 1.0 anymore - why limit yourself to SQL:86? The latest versions of MariaDB support the features of SQL:99 (common table expressions), SQL:2003 (window functions), SQL:2011 (system-versioned tables), and SQL:2016 (JSON), which allows you to build more complex (for example, hierarchical) models data and write simpler and faster queries.

This talk will describe two python extensions for gdb: @PrettyPrinter decorator — an easy approach to writing new pretty printers for your data, and DUEL — a high level data exploration language, a very powerful but easy way of examining complex data structures.

New MariaDB major release is out of the door. It has new unique features, performance enhancements, as well as better MySQL compatibility. This talk will go over everything new that MariaDB 10.2 has to offer. It will describe all new features, both MySQL compatible, and MariaDB-only ones and show usage examples and practical use cases.