Fixup reserve_with_scope_using_optimized_postgres

.github/workflows/ci.yml

@@ -216,6 +216,7 @@ jobs:
  with:
  ruby-version: ${{ matrix.ruby }}
  bundler-cache: true # runs 'bundle install' and caches installed gems automatically
+ cache-version: 2
  - name: Run tests
  env:
  BUNDLE_GEMFILE: ${{ matrix.gemfile }}

lib/delayed/backend/active_record.rb

@@ -133,19 +133,23 @@ def self.reserve_with_scope_using_optimized_postgres(ready_scope, worker, now)
  # Note: active_record would attempt to generate UPDATE...LIMIT like
  # SQL for Postgres if we use a .limit() filter, but it would not
  # use 'FOR UPDATE' and we would have many locking conflicts
+ subquery = ready_scope.limit(1).lock(true).select("id").to_sql
+
  # On PostgreSQL >= 9.5 we leverage SKIP LOCK to avoid multiple workers blocking each other
  # when attempting to get the next available job
  # https://www.postgresql.org/docs/9.5/sql-select.html#SQL-FOR-UPDATE-SHARE
- skip_locked = ""
- if connection.respond_to?(:postgresql_version) && connection.postgresql_version >= 90500
- skip_locked = " SKIP LOCKED"
+ if connection.send(:postgresql_version) >= 9_05_00 # rubocop:disable Style/NumericLiterals
+ subquery += " SKIP LOCKED"
  end
 
  quoted_name = connection.quote_table_name(table_name)
- subquery = ready_scope.limit(1).lock(true).select("id").to_sql
- sql = "UPDATE #{quoted_name} SET locked_at = ?, locked_by = ? WHERE id IN (#{subquery}#{skip_locked}) RETURNING *"
- reserved = find_by_sql([sql, now, worker.name])
- reserved[0]
+ find_by_sql(
+ [
+ "UPDATE #{quoted_name} SET locked_at = ?, locked_by = ? WHERE id IN (#{subquery}) RETURNING *",
+ now,
+ worker.name
+ ]
+ ).first
  end
 
  def self.reserve_with_scope_using_optimized_mysql(ready_scope, worker, now)