PGConf.Russia 2025

The focus of the presentation is on the challenges of building an application solution on PostgreSQL, specifically a high-load analytical data warehouse. Using the case of the company EVRAZ, we will demonstrate the impact of applying the Data Vault methodology on PostgreSQL and Greenplum databases for developing a unified production performance system.

We will discuss the difficulties and solutions, showcasing query plans for tasks such as updating directories and handling large objects, along with optimization examples. We will highlight coding nuances, problems related to populating the model, and issues with querying from the model.

This session will be useful for those planning to use or already facing challenges with the Data Vault methodology and performance issues in DWH on the open-source stack. We will compare technical implementation options for the Business Vault model layer, considering the specifics of PostgreSQL and Greenplum.

We will also cover 5 real problems that arise when operating a DWH and their solutions:

1. Transferring Business Vault object assembly logic from PostgreSQL to Greenplum.
2. Slower ETL performance when building the current state of Business Vault in PostgreSQL.
3. Slower Data Lineage construction in PostgreSQL and Greenplum.
4. Slow satellite queries in Greenplum.
5. Slow queries with "IN" or "OR" in the Business Vault layer.

What does a modern application developer need to transition from familiar cloud-based solutions to SQL databases?

This talk is a practical report on how we transformed an SQL database into a NoSQL-like solution with a developer-friendly interface. We’ll discuss:

What application developers expect from a data framework

How to implement declarative DDL, access control, and automation for reading and writing data

Simplified DML operations, pagination, and other essential features for application development

So much has been said about PostgreSQL as the result of its program code. But Postgres is not just code. It’s the people who create it, develop it, and... leave a piece of themselves through comments.

What stories can we uncover from the comments in PostgreSQL’s code? We’ll discover what the most popular word is, which comments have been in the code since the very first public commit, how the style of communication has evolved with the product, and how we can see the human side behind the lines of code and comments.

In some cases, business logic is implemented directly within the database. It's well known that maintaining and developing business logic becomes much easier when it's covered by tests. However, backend tests often treat the database as an external resource and don’t always interact with a live database.

This talk will introduce an enhanced version of the pgTap library, designed not only to facilitate unit testing and CI for database code but also to accelerate the development process itself.