PGConf.Russia 2025

t’s well known that pg_upgrade is the go-to tool for fast PostgreSQL upgrades. However, even with this tool, there are cases where the upgrade process takes far longer than expected.

In our case, upgrading a PostgreSQL database with 350,000 tables meant either waiting 3.5 hours or finding a better approach. By digging into the pg_upgrade source code, we discovered a way to speed up the process significantly. In this talk, we’ll share how we did it.

This presentation examines the challenges of migrating an application system from Oracle to Postgres, based on a real-world project. It provides a detailed discussion on logical replication of data from Postgres to ensure the possibility of reverting back to Oracle while maintaining the functionality of legacy reporting and integration.

This talk will cover key aspects of migrating from SQL Server to PostgreSQL, with a focus on converting stored procedures, triggers, views, functions, and other database objects. We’ll discuss the unique characteristics of each database system that can complicate code conversion, as well as unexpected factors that impact performance and correctness.

The session will be valuable for both experienced database professionals and those new to database migrations.

In this talk, we’ll:

• Share our experience of reworking the ECM system and platform that was originally built on C.Net + MS SQL for Windows to run on Linux + Postgres, while maintaining the option to install and operate on Windows + MS.

• Discuss migrating clients to new platforms with data migration.

• Share insights from operating the system with a high-load client (PG servers with 192 cores and 3 TB of RAM).