PgConf.Russia 2019

Virtualization in companies has become an alternative to the conservative "one task-one server" approach, which allows efficient use of hardware resources, centralized management of server infrastructure, saving energy and cooling resources. The report explains how to configure the VMware environment for intensive input / output PostgreSQL and profiling tools virtual infrastructure to monitor performance and resolve identified problems.

As any ordinary software developers, we just pursued a goal to develop a system robust for high loads, and even succeeded. The system architecture was fine, but the data volume was keeping increased and revealed the painful issues and errors that nobody had expected. We faced very strange queries seemed to be unbelievable. In my short talk I would like to share sad experience of arised-from-nothing high loads in DBMS and solving the challenge.

My presentation is about writing extensions in Postgres. I have written pg_threads that implements simplified POSIX thread API inside Postgres database. It adds a new powerful abstraction giving database developers new opportunities for writing parallel code thus taking advantage of multicore CPUs. There is an extra API for transactional and non-transactional IPC between threads. I also have an example application that takes advantage of this new API that scales linearly even across 2 nodes. The presentation is with live working demo using vagrant project with 2 VMs running Ubuntu and 2 Postgres 11 databases.

PostgreSQL provides possibility to create temporary tables. Though a temporary table is accessible only to a single session and is removed at the end of the session, all information about it is stored in the system catalogs of PostgreSQL. This is related to several issues, which make it difficult or impossible to use temporary tables in some cases. There are attempts to solve this feature, including in our company. But they have not yet succeeded, mainly because of the PostgreSQL engine. In the talk I want to tell about simple and small pg_variables extension. It allows you to create table variables along with scalar ones. I will tell how it can replace temporary tables, what advantages and disadvantages it has.