PGConf.Russia 2022

The more tables are involved with the query, the more difficult it is for the scheduler to choose a suitable execution plan (both time and memory usage increase). How can we "tell" the planner that it is better to connect this pair of tables first, and the rest can be connected later? What if we see that a part of our query can be improved, but the optimizer does not do this. In my presentation, I will talk about managing the order of connections. I will explain how we can influence the formation of a query plan using the standard "vanilla" PostgreSQL methods.

In June 2020, AlfaStrakhovaniye was obliged to use RSA 2.0 government services along with other insurance companies. It was the only way to sell car insurance in Russia. AlfaStrakhovaniye is a leader in car insurance, and its applications degraded under the pressure of calls. It wasn't planned. Postgres used a huge amount of CPU and memory. Nobody could tell what was going on. Degradation started and stopped for no reason. Dev Team and Postgres Pro experts solved that problem. MyBatis in Java services was the killer. Our story is about the development of applications for heavy workloads and technical ignorance while using frameworks.

In this presentation, we'll talk about the newest SQL/JSON features committed to PostgreSQL 15. We'll explain how to use them, where they can help and why they make a difference. Is PostgreSQL JSON implementation fully compliant with SQL:2016? In the meantime, the next generation of the SQL standard is being developed. What will the new standard include, and how will Postgres respond to it?

Usage of temporary tables in PostgreSQL causes additional issues like high server resources consumption and low query performance. However, sometimes you need to rely on them especially when you need to migrate your code from MS SQL, and your initial code employed them, and you had some logic implemented at the database level. This talk covers issues related to usage of temporary tables when migrating from MS SQL, and the ways to resolve them using built-in PostgreSQL features based on the scenarios contained in the code.