PGConf.Russia 2025

Currently, WAL files can be compressed with a ratio of up to 6x, but the existing compression system is inefficient.

In this talk, I’ll share my work on improving WAL compression.

As part of the import substitution process, we encountered the need to find a reliable alternative to Oracle. PostgreSQL was considered the primary candidate for replacement, but during the research, the "vanilla" version revealed a number of critical limitations that hindered a successful transition.

These issues included support for autonomous transactions, batch variables, and several other specifics. What is special about pg_settings? Why do we need autonomous transactions, and how do HOLD cursors relate to this? These and other topics will be discussed in our presentation, where we will also share our experience of implementing Postgres Pro Enterprise.

In today’s rapidly evolving technology landscape, PostgreSQL has emerged as a popular choice for organizations seeking to leverage the power of open-source databases while maintaining scalability, performance, and flexibility. 

As enterprises migrate from proprietary database systems like Oracle to PostgreSQL, developers face the challenge of adapting existing PL/SQL codebases to PL/pgSQL. Despite the similarities between these two procedural languages, significant differences in their syntax, performance characteristics, and ecosystem features require a thoughtful approach to migration and optimization. 

This session will focus on highlighting the key differences between Oracle’s PL/SQL and PostgreSQL’s PL/pgSQL, providing actionable insights on how to efficiently navigate these differences during migration. A deep dive will be taken into critical areas including compilation methodology, Code Debugging , Exception Handling, work_mem , Bulk Load and more.

This talk will explore different approaches to storing files in PostgreSQL, including:

• Simple table-based storage

• Large objects with pg_largeobject

• pgpro_sfile – a large object (pgpro_bfile) storage solution