---
title: "Postgres week in the Netherlands: PGDay Lowlands & Percona Live 2026"
description: "An account of three days in the Netherlands covers talks at PGDay Lowlands in Utrecht and Percona Live 2026 in Amsterdam, including a five-minute presentation on ClickHouse integrations and a PostgreSQL 19 monitoring session. pg_clickhouse uses a foreign data wrapper to expose ClickHouse tables as PostgreSQL foreign tables, allowing existing queries, ORMs, and dashboards to continue working while pushable work runs in ClickHouse; 15 of 22 TPC-H queries at scale factor 1 are fully pushed down. pg_stat_ch captures per-query execution events in a shared-memory ring buffer and sends batches to ClickHouse, dropping events rather than blocking PostgreSQL when ClickHouse is unavailable. The monitoring talk covered PostgreSQL 19 logging, WAL and I/O statistics, WAIT FOR, new system views, and multixact and wraparound changes. The post also reports talks on optimizer hints and plan stabilization, and says both conferences will return in 2027."
---

# Postgres week in the Netherlands: PGDay Lowlands & Percona Live 2026

[Clickhouse](https://yomu.fyi/company/clickhouse) · Sep 17, 2026

**Type:** Explainer

## Summary

An account of three days in the Netherlands covers talks at PGDay Lowlands in Utrecht and Percona Live 2026 in Amsterdam, including a five-minute presentation on ClickHouse integrations and a PostgreSQL 19 monitoring session. pg\_clickhouse uses a foreign data wrapper to expose ClickHouse tables as PostgreSQL foreign tables, allowing existing queries, ORMs, and dashboards to continue working while pushable work runs in ClickHouse; 15 of 22 TPC-H queries at scale factor 1 are fully pushed down. pg\_stat\_ch captures per-query execution events in a shared-memory ring buffer and sends batches to ClickHouse, dropping events rather than blocking PostgreSQL when ClickHouse is unavailable. The monitoring talk covered PostgreSQL 19 logging, WAL and I/O statistics, WAIT FOR, new system views, and multixact and wraparound changes. The post also reports talks on optimizer hints and plan stabilization, and says both conferences will return in 2027.

## Context

The post records attendance and speaking engagements at PGDay Lowlands in Utrecht on September 10, 2026, and Percona Live in Amsterdam on September 11. It also mentions a nationwide public transport strike on September 9, which ended before PGDay Lowlands proceeded as planned.

## Approach / What changed

pg\_clickhouse connects PostgreSQL to ClickHouse through a foreign data wrapper, importing ClickHouse tables as PostgreSQL foreign tables and pushing executable query work to ClickHouse. pg\_stat\_ch uses PostgreSQL hooks, a shared-memory ring buffer, and a background worker to batch raw query events to ClickHouse over its native protocol. The PostgreSQL 19 monitoring session organized changes into logging, WAL and I/O, WAIT FOR, system views, and multixacts and wraparound.

## Takeaways

- pg\_clickhouse lets existing PostgreSQL queries, ORM-generated SQL, and dashboards access ClickHouse through foreign tables; 15 of 22 TPC-H queries at scale factor 1 are fully pushed down.
- pg\_stat\_ch records raw per-query timing, buffer, WAL, CPU, application, client, and error data, then sends batches to ClickHouse for historical analysis and percentiles.
- PostgreSQL 19 monitoring changes include log\_lock\_waits enabled by default, wal\_fpi\_bytes, WAIT FOR for asynchronous standby read-your-writes semantics, three new system views, and a wraparound warning threshold raised from 40 million to 100 million transactions.

## FAQ

### What happens when ClickHouse is slow or unreachable with pg\_stat\_ch?

pg\_stat\_ch deliberately provides no back-pressure. Events are dropped and counted, so PostgreSQL does not wait for ClickHouse.

### How does pg\_clickhouse preserve existing PostgreSQL applications?

It imports ClickHouse tables as foreign tables in a PostgreSQL schema with mapped types. Changing search\_path lets existing read queries, ORMs, and dashboards run without modification.

### How do PostgreSQL 19's plan-advice modules differ from classic optimizer hints?

pg\_plan\_advice and pg\_stash\_advice target plan stabilization rather than classic hints. They constrain the planner to plans it would already have considered, with advice that can be pinned or stored per query ID.

**Tags:** [ClickHouse](https://yomu.fyi/topic/clickhouse), [Monitoring](https://yomu.fyi/topic/monitoring), [Postgres](https://yomu.fyi/topic/postgres)

- Source: [Clickhouse](https://clickhouse.com/blog/postgres-week-in-the-netherlands-pgday-lowlands-percona-live-2026)
- Source URL: https://clickhouse.com/blog/postgres-week-in-the-netherlands-pgday-lowlands-percona-live-2026
- Ingested by Yomu: 2026-09-17T14:06:14.075Z

[Read original post](https://clickhouse.com/blog/postgres-week-in-the-netherlands-pgday-lowlands-percona-live-2026)