PgConf.Russia 2019

This report focuses on the continuation of transferring our ECM “Priority” from MS SQL to Postgres. Technical solutions, issues of rewriting from T-SQL to plpgsql, optimization of the effective code and moving data will be covered. Additionally, there will be considered aspects of pgplsql performance testing to find the “bad code” of pgplsql as a candidate for optimization. The main objective of the presentation is to answer the question: "We have it in T-SQL - how to transfer it in PG?". The report is intended for junior Postgres developers and is a continuation of the previous report made at the conference in 2017(https://youtu.be/v6_4Szr8t14).

Postgres is known for it extensibility, which made it the universal database, that means it can meet the requirements of practically any project. Many extensions are well-known and widely used, for example, PostGIS extension - de-facto standard of open source GIS, hstore - an extension for storing and manipulation of arbitrary key/value pairs. I will talk about less known but useful PostgreSQL extensions, which provides a new functionaliy and/or improve the performance of PostgreSQL.

PostgreSQL was designed to be extensible, it provides an API to application developers to extend PostgreSQL functionality and/or improve the performance for specific data and workloads. It is important that there is no need of having expertise of core developers, and these new functionality could be added online without restarting of database server. Application developer can create various database objects, such as functions, data types, operators, indexes, and even new access methods.

I will present my choice of two extensions out of hundreds:

vops - greatly improves the performance of Postgres for OLAP queries using vector operations, pg_variables - provides session variables for storing scalars and relations, useful for generating reports on read-only replicas.

JSONB in PostgreSQL has interesting properties for design and development of business systems with heavy domain, helping to fight against complexity and variability. We will discuss the trade-offs of the JSONB approach. Using an open source project for Health IT - fhirbase we will:

• load synthetic medical data into PostgreSQL
• learn how to search and index this data (gin, jsquery, json-knife)
• use JSON aggregation to build complex queries (GraphQL)
• see how this data can be modified and validated
• discuss architecture consequences of JSONB usage

Technical requirements:

• docker
• docker-compose

Detailed prerequisites

In this session we will deep dive into the exciting features of Amazon RDS for PostgreSQL, including new versions of PostgreSQL releases, new extensions, larger instances. We will also show benchmarks of new RDS instance types, and their value proposition. We will also look at how high availability and read scaling works on RDS PostgreSQL. We will also explore lessons we have learned managing a large fleet of PostgreSQL instances, including important tunables and possible gotchas around pg_upgrade.