ankane/pghero · error · PgHero::NotEnabled

Query hash stats not enabled

Error message

Query hash stats not enabled

What it means

query_hash_stats(query_hash) charts a single query's historical performance from the pghero_query_stats/pghero_queries tables that pghero's stats capture maintains. Unlike current stats (pg_stat_statements), this requires the historical pipeline to be configured; when historical_query_stats_enabled? is false it raises NotEnabled "Query hash stats not enabled".

Source

Thrown at lib/pghero/methods/query_stats.rb:158

        db_query_stats = query_stats(limit: 100)
        if db_query_stats.any? && reset_query_stats(raise_errors: raise_errors)
          insert_query_stats(db_query_stats, captured_at)
        end
      end

      def clean_query_stats(before: nil)
        before ||= 14.days.ago
        PgHero::QueryStats.where(database: id).where("captured_at < ?", before).delete_all
      end

      def slow_queries(query_stats: nil, **options)
        query_stats ||= self.query_stats(**options)
        query_stats.select { |q| q[:calls].to_i >= slow_query_calls.to_i && q[:average_time].to_f >= slow_query_ms.to_f }
      end

      def query_hash_stats(query_hash, user: nil, current: true)
        if !historical_query_stats_enabled?
          raise NotEnabled, "Query hash stats not enabled"
        end

        start_at = 24.hours.ago
        # specify pghero_queries.query in case pghero_query_stats.query exists
        sql = <<~SQL
          SELECT
            captured_at,
            total_time,
            calls,
            (SELECT regexp_matches(pghero_queries.query, '.*/\\*(.+?)\\*/'))[1] AS origin
          FROM
            pghero_query_stats
          INNER JOIN
            pghero_queries ON pghero_queries.id = pghero_query_stats.query_id
          WHERE
            database = :id
            AND captured_at >= :start_at
            AND query_hash = :query_hash

View on GitHub (pinned to 7edb57986f)

Solutions

1. Set up historical query stats: configure the stats database (stats_database_url or the default), install the stats tables (pghero stats migration), and schedule pghero:capture_query_stats -a
2. Guard the call: check database.historical_query_stats_enabled? before invoking query_hash_stats
3. Verify capture is enabled for the specific database: config key capture_query_stats must not be false

if database.historical_query_stats_enabled?
  stats = database.query_hash_stats(query_hash)
end

begin
  database.query_hash_stats(query_hash)
rescue PgHero::NotEnabled
  # historical stats are optional - fall back to current stats or hide the view
  render_not_available("Historical query stats are not configured")
end

When it happens

Trigger: Calling PgHero.database.query_hash_stats(12345) in console or opening a query's info view on an installation that never set up the stats database (no stats_database_url / no stats capture schedule / migration not installed), or where capture_query_stats is disabled for that database.

Common situations: Fresh pghero installs that show the Queries tab (current stats work via pg_stat_statements) but never ran the historical setup steps; environments where the pghero stats migration ran on a different database; disabling capture_query_stats in pghero.yml.

Related errors

• Query stats not enabled
• Historical query stats not enabled
• Invalid sort
• Database not found: #{database}
• User not found: #{user}

AI-assisted analysis of ankane/pghero@7edb57986f (2026-08-21). Data as JSON: /api/errors/9f7762a224a52015. Report an issue: GitHub.