PGConf.Russia 2018

This report is about my PostgreSQL extension pg_profile. This extension all you need to create periodic statistics snapshots and to keep them. You can build a report on one or many serial snapshots. This report will contain statistics information about database workload in specified time period. It is very useful to start investigation on performance degragation or excessive resoure consumption in the past.

A database is one of the key components in any information system, requiring the monitoring of multiple metrics. The talk highlights examples and approaches of monitoring and analysis of PostgreSQL performance that allow to minimize the load on the database server from the monitoring and data collection system for the subsequent analysis of problem situations.

• Quantum effects or as an observer affect the observed system
• Features of collecting metrics while monitoring the database with Zabbix
• Data collection for analytics and visualization PostgreSQL queries with rsyslog + kafka + clickhouse + grafana
• Operational Analysis Tools for DB loglile

In this talk I will share the experience of migration, NoSQL data to a relational view convert, and tell you how we managed to speed up the application in 2 times.

Initially, we used PosgtgreSQL and MongoDB to store all the data. In practice, we found out that the separation is extremely inconvenient. We spent a lot of time and attention on it.

My talk will describe how we moved the data from MongoDB to PostgreSQL using mosql. As a result, all the data can be received by one query now, and the table schema ensures data consistency.

Many of us know that it is MVCC that provides concurrency access to data in many relational databases that guarantee transactions consistency and isolation. But only deep understanding of the implementation of this mechanism in PostgreSQL allows us to better understand the processes in the database, to design the application logic and table structures to be the most effective in a high-load world. We'll take one of the processes in our product to understand how MVCC is implemented in PostgreSQL and we'll explain one of the peculiarity when seemingly unrelated activities can affect each other.