demarches-normaliennes/app/jobs/cron/purge_unattached_blobs_job.rb
2024-08-22 09:26:48 +02:00

25 lines
1.1 KiB
Ruby

# frozen_string_literal: true
class Cron::PurgeUnattachedBlobsJob < Cron::CronJob
self.schedule_expression = "every day at 00:30"
def perform
# .in_batches { _1.each... } is more efficient in this case that in_batches.each_record or find_each
# because it plucks only ids in a preliminary query, then load records with selected columns in batches by ids.
# This is faster than other batch strategies, which load at once selected columns with an ORDER BY in the same query, triggering timeouts.
#
# .where(created_at: 1.week.ago..1.day.ago) to limit the number of records to be joined
# to the attachments table because of the unattached scope. Otherwise, it is triggering timeouts.
#
# the creation of an index on created_at does not seem required yet.
#
# caveats: the job needs to be run at least once a week to avoid missing blobs
ActiveStorage::Blob
.where(created_at: 1.week.ago..1.day.ago)
.unattached
.select(:id, :service_name)
.in_batches do |relation|
relation.each(&:purge_later)
end
end
end