PGConf.Russia 2025

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.

Not a PgBouncer, But a Connection Pooler. Not Odyssey, But with Coroutines

If you’ve ever set up a high-availability PostgreSQL cluster, you’ve likely faced the challenge of redirecting traffic to the primary node after a failover.

Typically, this requires additional software to monitor cluster status and reroute traffic accordingly. To avoid a single point of failure, you may have had to implement failover handling within that layer. Additionally, you might have encountered PostgreSQL’s limitations on handling large numbers of concurrent client sessions, necessitating query pooling.

To solve these issues, we developed Proxima — a scalable, fault-tolerant proxy and connection pooler. Proxima automatically redirects traffic to the primary node and, in BiHA setups, seamlessly switches to a new primary in case of failure.

In this talk, I’ll cover why and how we built Proxima, the key architectural decisions behind the extension, and the

implementation details that enable it to handle 10,000+ concurrent client sessions.

We’ll also explore use cases and answer your questions.

Poolers play a crucial role in PostgreSQL database operations. In this talk, we’ll discuss the challenges we faced when using and implementing existing poolers and the benefits we gained by developing our own pooler.

Making changes to tables under production load is always a complex task. For example, when you need to change a column type (e.g., from int to bigint or from timestamp to timestamptz), or move a table to a different tablespace without losing any changes that occur during the data migration.

What if you have hundreds of such tables? With pg-transparent-alter-table, this is no longer a problem. These tasks can be solved with a single simple command:
$ pg_tat -h 0.0.0.0 -d mydb -c "alter table mytable alter column id bigint"

Key features include:

• You can specify any number of alter table commands at once.
• You can modify partitioned tables, supporting both the old inheritance-based partitioning and new declarative partitioning, including multi-level partitioning.
• You can interrupt the process at any stage and continue later without losing progress from previous stages.
• You can change your mind at any time, stop the execution, run "pg_tat --clean," and revert to the original state.
• Custom commands for changing column order.
• PostgreSQL version support: 11-17.

After more than 5 years of existence (previously called transparent-alter-type), the project has become a reliable tool actively used in production. I would like to share my experience and discuss its capabilities.