89 lines
3.8 KiB
Ruby
89 lines
3.8 KiB
Ruby
# frozen_string_literal: true
|
|
|
|
module Gitlab
|
|
module Database
|
|
module PartitioningMigrationHelpers
|
|
module ForeignKeyHelpers
|
|
include ::Gitlab::Database::SchemaHelpers
|
|
|
|
ERROR_SCOPE = 'foreign keys'
|
|
|
|
# Adds a foreign key with only minimal locking on the tables involved.
|
|
#
|
|
# In concept it works similarly to add_concurrent_foreign_key, but we have
|
|
# to add a special helper for partitioned tables for the following reasons:
|
|
# - add_concurrent_foreign_key sets the constraint to `NOT VALID`
|
|
# before validating it
|
|
# - Setting an FK to NOT VALID is not supported currently in Postgres (up to PG13)
|
|
# - Also, PostgreSQL will currently ignore NOT VALID constraints on partitions
|
|
# when adding a valid FK to the partitioned table, so they have to
|
|
# also be validated before we can add the final FK.
|
|
# Solution:
|
|
# - Add the foreign key first to each partition by using
|
|
# add_concurrent_foreign_key and validating it
|
|
# - Once all partitions have a foreign key, add it also to the partitioned
|
|
# table (there will be no need for a validation at that level)
|
|
# For those reasons, this method does not include an option to delay the
|
|
# validation, we have to force validate: true.
|
|
#
|
|
# source - The source (partitioned) table containing the foreign key.
|
|
# target - The target table the key points to.
|
|
# column - The name of the column to create the foreign key on.
|
|
# on_delete - The action to perform when associated data is removed,
|
|
# defaults to "CASCADE".
|
|
# name - The name of the foreign key.
|
|
#
|
|
def add_concurrent_partitioned_foreign_key(source, target, column:, on_delete: :cascade, name: nil)
|
|
assert_not_in_transaction_block(scope: ERROR_SCOPE)
|
|
|
|
partition_options = {
|
|
column: column,
|
|
on_delete: on_delete,
|
|
|
|
# We'll use the same FK name for all partitions and match it to
|
|
# the name used for the partitioned table to follow the convention
|
|
# used by PostgreSQL when adding FKs to new partitions
|
|
name: name.presence || concurrent_partitioned_foreign_key_name(source, column),
|
|
|
|
# Force the FK validation to true for partitions (and the partitioned table)
|
|
validate: true
|
|
}
|
|
|
|
if foreign_key_exists?(source, target, **partition_options)
|
|
warning_message = "Foreign key not created because it exists already " \
|
|
"(this may be due to an aborted migration or similar): " \
|
|
"source: #{source}, target: #{target}, column: #{partition_options[:column]}, "\
|
|
"name: #{partition_options[:name]}, on_delete: #{partition_options[:on_delete]}"
|
|
|
|
Gitlab::AppLogger.warn warning_message
|
|
|
|
return
|
|
end
|
|
|
|
partitioned_table = find_partitioned_table(source)
|
|
|
|
partitioned_table.postgres_partitions.order(:name).each do |partition|
|
|
add_concurrent_foreign_key(partition.identifier, target, **partition_options)
|
|
end
|
|
|
|
with_lock_retries do
|
|
add_foreign_key(source, target, **partition_options)
|
|
end
|
|
end
|
|
|
|
# Returns the name for a concurrent partitioned foreign key.
|
|
#
|
|
# Similar to concurrent_foreign_key_name (Gitlab::Database::MigrationHelpers)
|
|
# we just keep a separate method in case we want a different behavior
|
|
# for partitioned tables
|
|
#
|
|
def concurrent_partitioned_foreign_key_name(table, column, prefix: 'fk_rails_')
|
|
identifier = "#{table}_#{column}_fk"
|
|
hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
|
|
|
|
"#{prefix}#{hashed_identifier}"
|
|
end
|
|
end
|
|
end
|
|
end
|
|
end
|