52 lines
1.8 KiB
Ruby
52 lines
1.8 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
class AddUniqueIndexOnPreviewCardsStatuses < ActiveRecord::Migration[6.1]
|
|
disable_ddl_transaction!
|
|
|
|
def up
|
|
add_index :preview_cards_statuses, [:status_id, :preview_card_id], name: :preview_cards_statuses_pkey, algorithm: :concurrently, unique: true
|
|
rescue ActiveRecord::RecordNotUnique
|
|
deduplicate_and_reindex!
|
|
end
|
|
|
|
def down
|
|
remove_index :preview_cards_statuses, name: :preview_cards_statuses_pkey
|
|
end
|
|
|
|
private
|
|
|
|
def supports_concurrent_reindex?
|
|
@supports_concurrent_reindex ||= begin
|
|
version = select_one("SELECT current_setting('server_version_num') AS v")['v'].to_i
|
|
version >= 120_000
|
|
end
|
|
end
|
|
|
|
def deduplicate_and_reindex!
|
|
deduplicate_preview_cards!
|
|
|
|
if supports_concurrent_reindex?
|
|
safety_assured { execute 'REINDEX INDEX CONCURRENTLY preview_cards_statuses_pkey' }
|
|
else
|
|
remove_index :preview_cards_statuses, name: :preview_cards_statuses_pkey
|
|
add_index :preview_cards_statuses, [:status_id, :preview_card_id], name: :preview_cards_statuses_pkey, algorithm: :concurrently, unique: true
|
|
end
|
|
rescue ActiveRecord::RecordNotUnique
|
|
retry
|
|
end
|
|
|
|
def deduplicate_preview_cards!
|
|
# Statuses should have only one preview card at most, even if that's not the database
|
|
# constraint we will end up with
|
|
duplicate_ids = select_all('SELECT status_id FROM preview_cards_statuses GROUP BY status_id HAVING count(*) > 1;').rows
|
|
|
|
duplicate_ids.each_slice(1000) do |ids|
|
|
# This one is tricky: since we don't have primary keys to keep only one record,
|
|
# use the physical `ctid`
|
|
safety_assured do
|
|
execute "DELETE FROM preview_cards_statuses p WHERE p.status_id IN (#{ids.join(', ')}) AND p.ctid NOT IN (SELECT q.ctid FROM preview_cards_statuses q WHERE q.status_id = p.status_id LIMIT 1)"
|
|
end
|
|
end
|
|
end
|
|
end
|