May 30, 2019
 Percona Live Open Source Database Conference 2019
  Øystein Grøvlen, Benny Wang

The upcoming version of POLARDB supports parallel execution of SQL queries.

In this presentation, we will show how query execution times may be significantly improved by using multiple threads to scan a table or index in parallel. Each thread will be able to do filtering and aggregation in order to reduce the amount of data to be processed by the query coordinator. Parallel join execution is also supported. We will discuss which type of queries will benefit from this feature and present results that show performance and scalability characteristics. We will also show how to control the degree of parallelism for a query and discuss other aspects of tuning parallel queries.



About the Authors

Øystein Grøvlen

Øystein Grøvlen is a Senior Staff Engineer in Alibaba Cloud, where he works in the Database Products Group. Before joining Alibaba, Øystein worked for 10 years in the MySQL optimizer team at Sun/Oracle. At Sun Microsystems, he was also a contributor on the Apache Derby project and Sun's Architectural Lead on Java DB. Prior to that, he worked for 10 years on development of Clustra, a highly available DBMS. Øystein has been talking about the MySQL Optimizer at several conferences over the years. Dr. Grøvlen has a PhD in Computer Science from the Norwegian University of Science and Technology. Øystein is a native Norwegian, but currently lives in Hangzhou, China.
 

Benny Wang

Benny Wang is a Staff Engineer in Alibaba Cloud, where he works in the Database Products Group. Before joining Alibaba, Benny worked for 3 years in the MySQL optimizer team at Oracle. Benny has been working on database optimizer for almost 10 years. Worked on both Mysql and PostgreSQL optimizer during the past few years.