Presented by:
Peter Smith
Peter is a PostgreSQL significant contributor and member of Fujitsu's Open Source Software team, specialising in logical replication development. He actively reviews enhancements to PostgreSQL's replication capabilities. Peter also writes technical blogs sharing insights on PostgreSQL development and internals.
Ajin Cherian
Ajin is a PostgreSQL significant contributor and member of Fujitsu’s Open Source Software team, specialising in logical replication development. He has co-authored patches that added logical decoding of two-phase transactions (PostgreSQL 14), the two_phase subscription option for replicating prepared transactions (PostgreSQL 15), and the skipping of empty transactions in logical replication (PostgreSQL 15). He has also contributed to the synchronisation of logical replication slots to standbys for failover (PostgreSQL 17) and worked on conflict detection and resolution in logical replication.
This talk will be co-presented by Ajin Cherian and Peter Smith.
PostgreSQL 19 brings significant enhancements to logical replication, giving administrators far greater control over what gets replicated and how. In this talk, two PostgreSQL contributors who worked directly on these features cover the same new functionality from two complementary angles.
Ajin Cherian opens with the sequence thread from an upgrade-workflow perspective. Logical replication has made major version upgrades significantly easier by allowing physical standbys to be converted into logical subscribers with minimal downtime — but until PostgreSQL 19, sequence synchronization remained a key gap. Ajin explores why synchronized sequences matter, how the new ALTER SUBSCRIPTION ... REFRESH SEQUENCES command works, and how to integrate it into a reliable upgrade workflow using pg_createsubscriber.
Peter Smith then revisits the same sequence synchronization feature from the system catalog’s point of view. Starting from the PG18 baseline publication and subscription catalogs, Peter walks through exactly what changed under the hood — how FOR ALL SEQUENCES is represented on the publisher, how REFRESH PUBLICATION and REFRESH SEQUENCES differ internally, and how the tablesync and sequencesync workers pick up pending work. Peter then turns to PostgreSQL 19’s other major publication enhancement, FOR ALL TABLES EXCEPT, covering its syntax, catalog representation, and practical use, before closing with a look at related EXCEPT variants proposed for a future release.
- Date:
- 2026 October 30 09:50 +11
- Duration:
- 40 min
- Room:
- Oxford 1 + 2
- Conference:
- PG Down Under 2026
- Language:
- Track:
- Essentials
- Difficulty:
- Medium