diff options
| -rw-r--r-- | db/migrate/20180812173710_copy_status_stats.rb | 50 |
1 files changed, 41 insertions, 9 deletions
diff --git a/db/migrate/20180812173710_copy_status_stats.rb b/db/migrate/20180812173710_copy_status_stats.rb index 850aa9c13..ff10c18d9 100644 --- a/db/migrate/20180812173710_copy_status_stats.rb +++ b/db/migrate/20180812173710_copy_status_stats.rb @@ -3,15 +3,10 @@ class CopyStatusStats < ActiveRecord::Migration[5.2] def up safety_assured do - Status.unscoped.select('id').find_in_batches(batch_size: 5_000) do |statuses| - execute <<-SQL.squish - INSERT INTO status_stats (status_id, reblogs_count, favourites_count, created_at, updated_at) - SELECT id, reblogs_count, favourites_count, created_at, updated_at - FROM statuses - WHERE id IN (#{statuses.map(&:id).join(', ')}) - ON CONFLICT (status_id) DO UPDATE - SET reblogs_count = EXCLUDED.reblogs_count, favourites_count = EXCLUDED.favourites_count - SQL + if supports_upsert? + up_fast + else + up_slow end end end @@ -19,4 +14,41 @@ class CopyStatusStats < ActiveRecord::Migration[5.2] def down # Nothing end + + private + + def supports_upsert? + version = select_one("SELECT current_setting('server_version_num') AS v")['v'].to_i + version >= 90500 + end + + def up_fast + say 'Upsert is available, importing counters using the fast method' + + Status.unscoped.select('id').find_in_batches(batch_size: 5_000) do |statuses| + execute <<-SQL.squish + INSERT INTO status_stats (status_id, reblogs_count, favourites_count, created_at, updated_at) + SELECT id, reblogs_count, favourites_count, created_at, updated_at + FROM statuses + WHERE id IN (#{statuses.map(&:id).join(', ')}) + ON CONFLICT (status_id) DO UPDATE + SET reblogs_count = EXCLUDED.reblogs_count, favourites_count = EXCLUDED.favourites_count + SQL + end + end + + def up_slow + say 'Upsert is not available in PostgreSQL below 9.5, falling back to slow import of counters' + + # We cannot use bulk INSERT or overarching transactions here because of possible + # uniqueness violations that we need to skip over + Status.unscoped.select('id, reblogs_count, favourites_count, created_at, updated_at').find_each do |status| + begin + params = [[nil, status.id], [nil, status.reblogs_count], [nil, status.favourites_count], [nil, status.created_at], [nil, status.updated_at]] + exec_insert('INSERT INTO status_stats (status_id, reblogs_count, favourites_count, created_at, updated_at) VALUES ($1, $2, $3, $4, $5)', nil, params) + rescue ActiveRecord::RecordNotUnique + next + end + end + end end |