{
  "id": 16852267,
  "title": "PostgreSQL 19 - Monitoring Lock Contention and Fast-Path Overflow with pg_stat_lock",
  "url": "https://urgent.news/2026/10/28/postgresql-19-monitoring-lock-contention-and-fast-path-overflow-with",
  "topic": "tech",
  "section": "Tech",
  "published": "2026-10-28T05:23:06.000Z",
  "source": {
    "name": "Dev.to",
    "slug": "dev-to",
    "url": "https://dev.to/vahidusefzadeh/postgresql-19-monitoring-lock-contention-and-fast-path-overflow-with-pgstatlock-454"
  },
  "original_language": "en",
  "account": "PostgreSQL 19 introduces a new view called pg_stat_lock, which provides valuable insights into lock activity within a database cluster. This feature enables administrators to monitor lock contention, measure the time spent waiting for locks, and identify instances where relation locks exceed the available fast-path slots. In this report, I will showcase the capabilities of pg_stat_lock through two real-world examples.\n\nThe pg_stat_lock view consists of several columns, including locktype (representing the type of lockable object), waits (the number of qualifying lock waits), wait_time (total time spent waiting for locks in milliseconds), fastpath_exceeded (the count of times a lock could not be acquired through the fast path due to exceeded slots), and stats_reset (the timestamp when statistics were last reset). Initially, all counters are set to zero.\n\nWhen examining the results, the view returns 12 rows, with one row dedicated to each lock type. The locktype column indicates the type of object, such as relation, transaction ID, page, tuple, or userlock. The waits and wait_time columns track the number of lock waits and the total time spent waiting, respectively. The fastpath_exceeded column reveals how often a lock was unable to be acquired through the fast path due to all available slots being occupied. Lastly, the stats_reset column indicates the time when the statistics were last reset.\n\nAn essential aspect to note is that waits and wait_time only include lock waits that surpass the deadlock_timeout threshold and result in successful lock acquisition. In my testing environment, the deadlock_timeout is set to 1 second (1 s).\n\nTo demonstrate the utility of pg_stat_lock, let's explore two practical scenarios. The first scenario focuses on lock waits caused by concurrent transactions, while the second scenario investigates lock contention in a specific table, tbl_counter, where two sessions attempt to update the same counter row simultaneously. Before proceeding with these experiments, we first reset the lock statistics using the pg_stat_reset_shared function.",
  "summary": "PostgreSQL 19 introduces the pg_stat_lock view, which provides cumulative statistics about lock activity across the database cluster. It helps database administrators investigate lock contention, measure time spent waiting for locks, and identify situations where relation locks exceed the available fast-path slots. In this article, I will demonstrate these capabilities through two practical…",
  "key_points": [
    "pgstatlock view introduced in PostgreSQL 19",
    "Monitors lock contention, lock wait times, fast-path overflow",
    "Demonstrated with concurrent transactions and table contention examples"
  ],
  "editors_take": "The introduction of the pgstatlock view empowers database administrators to diagnose performance bottlenecks by providing direct visibility into lock contention and the exhaustion of fast-path slots.",
  "illustration": null,
  "coverage": {
    "outlets": 1,
    "also_reported_by": []
  },
  "ai_generated": true,
  "disclaimer": "Summaries, key points and the editor’s take are written by software from other outlets’ reporting and may contain errors — always check the linked original."
}