PGConf.Russia 2022

Replication is one of the important mechanisms designed to provide database fault tolerance and scalability. In our practice, we regularly encounter the problem of low replication performance. This prompted us to investigate the factors that affect the speed of physical replication. In this presentation, I will talk about our findings. I will also demonstrate the differences in replication performance for various versions of PostgreSQL.

The release cycle for version 15 is nearing completion. At the time of the presentation, the complete list of changes will not be known. But for sure there will be something to talk about.

Previously, we have explained the internals of Avito, discussed, where and how we store your classifieds, and how they appear on the search results. In the recent 3-4 a lot has changed in Avito. We got rid of logical replication, stopped using standby servers for reads, removed nearly all stored procedures and our custom failover solution, migrated all our classifieds into a sharded DBMS, switched from the monolith app to microservices. I'll explain why we made such decisions, list some of the problems we encountered and describe the current state of our development process.

Tasks for migrations from the classic commercial DBMSs to open-source solutions are still relevant nowadays. Tools used to migrate Oracle applications to PostgreSQL has already proved to be efficient. But what if you have SQL Server? We want to introduce you to Babelfish, a OSS solution based on PostgreSQL 13. Babelfish supports TDS network protocol, T-SQL language, and SQL extensions specific to SQL Server. However, it isn't that simple. In our talk, we'll cover the features ensuring compatibility with SQL Server, existing problems and ways to solve them. Bonus: we'll also share the story on how we added the Babelfish support in DBeaver using the JDBC driver from Microsoft.