discourse/db/migrate/20240820123404_copy_notifications_id_indexes.rb
Bianca Nenciu 15f036bafa
DEV: Migrate notifications#id and related columns to bigint (#28584)
* DEV: Migrate notifications#id to bigint (#28444)

The `notifications.id` column is the most probable column to run out of
values. This is because it is an `int` column that has only 2147483647
values and many notifications are generated on a regular basis in an
active community. This commit migrates the column to `bigint`.

These migrations do not use `ALTER TABLE ... COLUMN ... TYPE` in order
to avoid the `ACCESS EXCLUSIVE` lock on the entire table. Instead, they
create a new `bigint` column, copy the values to the new column and
then sets the new column as primary key.

Related columns (see `user_badges`, `shelved_notifications`) will
be migrated in a follow-up commit.

* DEV: Fix bigint notifications id migration to deal with public schema (#28538)

Follow up to 799a45a291

* DEV: Migrate shelved_notifications#notification_id to bigint (#28549)

DEV: Migrate shelved_notifications#notification_id to bigint

The `notifications.id` has been migrated to `bigint` in previous commit
799a45a291.

* DEV: Fix annotations (#28569)

Follow-up to ec8ba5a0b9

* DEV: Migrate user_badges#notification_id to bigint (#28546)

The `notifications.id` has been migrated to bigint in previous commit
799a45a291. This commit migrates one of
the related columns, `user_badges.notification_id`, to `bigint`.

* DEV: Migrate `User#seen_notification_id` to `bigint` (#28572)

`Notification#id` was migrated to `bigint` in 799a45a291

* DEV: Migrate `Chat::NotificationMention#notification_id` to `bigint` (#28571)

`Notification#id` was migrated to `bigint` in 799a45a291

---------

Co-authored-by: Alan Guo Xiang Tan <gxtan1990@gmail.com>
2024-08-29 18:06:55 +03:00

40 lines
1.2 KiB
Ruby

# frozen_string_literal: true
class CopyNotificationsIdIndexes < ActiveRecord::Migration[7.0]
disable_ddl_transaction!
def up
# Short-circuit if the table has been migrated already
result =
execute(
"SELECT data_type FROM information_schema.columns WHERE table_name = 'notifications' AND column_name = 'id' LIMIT 1",
)
data_type = result[0]["data_type"]
return if data_type.downcase == "bigint"
# Copy existing indexes and suffix them with `_bigint`
results =
execute(
"SELECT indexname, indexdef FROM pg_indexes WHERE tablename = 'notifications' AND indexdef SIMILAR TO '%\\mid\\M%' AND schemaname = 'public'",
)
results.each do |res|
indexname, indexdef = res["indexname"], res["indexdef"]
indexdef = indexdef.gsub(/\b#{indexname}\b/, "#{indexname}_bigint")
indexdef =
indexdef.gsub(
/\bCREATE (UNIQUE )?INDEX\b/,
"CREATE \\1INDEX CONCURRENTLY",
) if !Rails.env.test?
indexdef = indexdef.gsub(/\bid\b/, "new_id")
execute "DROP INDEX #{Rails.env.test? ? "" : "CONCURRENTLY"} IF EXISTS #{indexname}_bigint"
execute(indexdef)
end
end
def down
raise ActiveRecord::IrreversibleMigration
end
end