bd4bbba98a
As pointed out on Discourse: https://discourse.joinmastodon.org/t/obscure-wtf-error-message-running-migrations-for-3-1/2524 The message the administrators were getting was telling them to log in to the "GitLab database" and also mentions MySQL
999 lines
36 KiB
Ruby
999 lines
36 KiB
Ruby
# frozen_string_literal: true
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# This file is copied almost entirely from GitLab, which has done a large
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# amount of work to ensure that migrations can happen with minimal downtime.
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# Many thanks to those engineers.
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# Changes have been made to remove dependencies on other GitLab files and to
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# shorten temporary column names.
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# Documentation on using these functions (and why one might do so):
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# https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/what_requires_downtime.md
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# The file itself:
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# https://gitlab.com/gitlab-org/gitlab-ce/blob/master/lib/gitlab/database/migration_helpers.rb
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# It is licensed as follows:
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# Copyright (c) 2011-2017 GitLab B.V.
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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# This is bad form, but there are enough differences that it's impractical to do
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# otherwise:
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# rubocop:disable all
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module Mastodon
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module MigrationHelpers
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# Stub for Database.postgresql? from GitLab
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def self.postgresql?
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ActiveRecord::Base.configurations[Rails.env]['adapter'].casecmp('postgresql').zero?
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end
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# Stub for Database.mysql? from GitLab
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def self.mysql?
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ActiveRecord::Base.configurations[Rails.env]['adapter'].casecmp('mysql2').zero?
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end
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# Model that can be used for querying permissions of a SQL user.
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class Grant < ActiveRecord::Base
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self.table_name =
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if Mastodon::MigrationHelpers.postgresql?
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'information_schema.role_table_grants'
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else
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'mysql.user'
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end
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def self.scope_to_current_user
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if Mastodon::MigrationHelpers.postgresql?
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where('grantee = user')
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else
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where("CONCAT(User, '@', Host) = current_user()")
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end
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end
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# Returns true if the current user can create and execute triggers on the
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# given table.
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def self.create_and_execute_trigger?(table)
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priv =
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if Mastodon::MigrationHelpers.postgresql?
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where(privilege_type: 'TRIGGER', table_name: table)
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else
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where(Trigger_priv: 'Y')
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end
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priv.scope_to_current_user.any?
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end
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end
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BACKGROUND_MIGRATION_BATCH_SIZE = 1000 # Number of rows to process per job
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BACKGROUND_MIGRATION_JOB_BUFFER_SIZE = 1000 # Number of jobs to bulk queue at a time
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# Gets an estimated number of rows for a table
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def estimate_rows_in_table(table_name)
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exec_query('SELECT reltuples FROM pg_class WHERE relname = ' +
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"'#{table_name}'").to_a.first['reltuples']
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end
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# Adds `created_at` and `updated_at` columns with timezone information.
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#
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# This method is an improved version of Rails' built-in method `add_timestamps`.
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#
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# Available options are:
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# default - The default value for the column.
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# null - When set to `true` the column will allow NULL values.
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# The default is to not allow NULL values.
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def add_timestamps_with_timezone(table_name, **options)
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options[:null] = false if options[:null].nil?
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[:created_at, :updated_at].each do |column_name|
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if options[:default] && transaction_open?
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raise '`add_timestamps_with_timezone` with default value cannot be run inside a transaction. ' \
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'You can disable transactions by calling `disable_ddl_transaction!` ' \
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'in the body of your migration class'
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end
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# If default value is presented, use `add_column_with_default` method instead.
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if options[:default]
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add_column_with_default(
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table_name,
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column_name,
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:datetime_with_timezone,
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default: options[:default],
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allow_null: options[:null]
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)
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else
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add_column(table_name, column_name, :datetime_with_timezone, options)
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end
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end
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end
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# Creates a new index, concurrently when supported
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#
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# On PostgreSQL this method creates an index concurrently, on MySQL this
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# creates a regular index.
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#
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# Example:
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#
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# add_concurrent_index :users, :some_column
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#
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# See Rails' `add_index` for more info on the available arguments.
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def add_concurrent_index(table_name, column_name, **options)
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if transaction_open?
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raise 'add_concurrent_index can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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if MigrationHelpers.postgresql?
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options = options.merge({ algorithm: :concurrently })
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disable_statement_timeout
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end
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add_index(table_name, column_name, options)
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end
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# Removes an existed index, concurrently when supported
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#
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# On PostgreSQL this method removes an index concurrently.
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#
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# Example:
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#
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# remove_concurrent_index :users, :some_column
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#
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# See Rails' `remove_index` for more info on the available arguments.
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def remove_concurrent_index(table_name, column_name, **options)
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if transaction_open?
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raise 'remove_concurrent_index can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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if supports_drop_index_concurrently?
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options = options.merge({ algorithm: :concurrently })
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disable_statement_timeout
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end
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remove_index(table_name, options.merge({ column: column_name }))
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end
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# Removes an existing index, concurrently when supported
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#
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# On PostgreSQL this method removes an index concurrently.
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#
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# Example:
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#
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# remove_concurrent_index :users, "index_X_by_Y"
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#
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# See Rails' `remove_index` for more info on the available arguments.
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def remove_concurrent_index_by_name(table_name, index_name, **options)
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if transaction_open?
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raise 'remove_concurrent_index_by_name can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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if supports_drop_index_concurrently?
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options = options.merge({ algorithm: :concurrently })
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disable_statement_timeout
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end
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remove_index(table_name, options.merge({ name: index_name }))
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end
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# Only available on Postgresql >= 9.2
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def supports_drop_index_concurrently?
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return false unless MigrationHelpers.postgresql?
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version = select_one("SELECT current_setting('server_version_num') AS v")['v'].to_i
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version >= 90200
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end
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# Adds a foreign key with only minimal locking on the tables involved.
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#
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# This method only requires minimal locking when using PostgreSQL. When
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# using MySQL this method will use Rails' default `add_foreign_key`.
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#
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# source - The source table containing the foreign key.
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# target - The target table the key points to.
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# column - The name of the column to create the foreign key on.
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# on_delete - The action to perform when associated data is removed,
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# defaults to "CASCADE".
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def add_concurrent_foreign_key(source, target, column:, on_delete: :cascade, target_col: 'id')
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# Transactions would result in ALTER TABLE locks being held for the
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# duration of the transaction, defeating the purpose of this method.
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if transaction_open?
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raise 'add_concurrent_foreign_key can not be run inside a transaction'
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end
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# While MySQL does allow disabling of foreign keys it has no equivalent
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# of PostgreSQL's "VALIDATE CONSTRAINT". As a result we'll just fall
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# back to the normal foreign key procedure.
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if MigrationHelpers.mysql?
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return add_foreign_key(source, target,
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column: column,
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on_delete: on_delete)
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else
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on_delete = 'SET NULL' if on_delete == :nullify
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end
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disable_statement_timeout
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key_name = concurrent_foreign_key_name(source, column, target_col)
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# Using NOT VALID allows us to create a key without immediately
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# validating it. This means we keep the ALTER TABLE lock only for a
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# short period of time. The key _is_ enforced for any newly created
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# data.
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execute <<-EOF.strip_heredoc
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ALTER TABLE #{source}
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ADD CONSTRAINT #{key_name}
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FOREIGN KEY (#{column})
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REFERENCES #{target} (#{target_col})
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#{on_delete ? "ON DELETE #{on_delete.upcase}" : ''}
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NOT VALID;
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EOF
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# Validate the existing constraint. This can potentially take a very
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# long time to complete, but fortunately does not lock the source table
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# while running.
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execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{key_name};")
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end
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# Returns the name for a concurrent foreign key.
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#
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# PostgreSQL constraint names have a limit of 63 bytes. The logic used
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# here is based on Rails' foreign_key_name() method, which unfortunately
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# is private so we can't rely on it directly.
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def concurrent_foreign_key_name(table, column, target_col)
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"fk_#{Digest::SHA256.hexdigest("#{table}_#{column}_#{target_col}_fk").first(10)}"
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end
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# Long-running migrations may take more than the timeout allowed by
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# the database. Disable the session's statement timeout to ensure
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# migrations don't get killed prematurely. (PostgreSQL only)
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def disable_statement_timeout
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execute('SET statement_timeout TO 0') if MigrationHelpers.postgresql?
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end
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# Updates the value of a column in batches.
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#
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# This method updates the table in batches of 5% of the total row count.
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# This method will continue updating rows until no rows remain.
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#
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# When given a block this method will yield two values to the block:
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#
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# 1. An instance of `Arel::Table` for the table that is being updated.
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# 2. The query to run as an Arel object.
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#
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# By supplying a block one can add extra conditions to the queries being
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# executed. Note that the same block is used for _all_ queries.
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#
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# Example:
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#
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# update_column_in_batches(:projects, :foo, 10) do |table, query|
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# query.where(table[:some_column].eq('hello'))
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# end
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#
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# This would result in this method updating only rows where
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# `projects.some_column` equals "hello".
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#
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# table - The name of the table.
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# column - The name of the column to update.
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# value - The value for the column.
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#
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# Rubocop's Metrics/AbcSize metric is disabled for this method as Rubocop
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# determines this method to be too complex while there's no way to make it
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# less "complex" without introducing extra methods (which actually will
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# make things _more_ complex).
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#
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# rubocop: disable Metrics/AbcSize
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def update_column_in_batches(table_name, column, value)
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if transaction_open?
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raise 'update_column_in_batches can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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table = Arel::Table.new(table_name)
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total = estimate_rows_in_table(table_name).to_i
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if total == 0
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count_arel = table.project(Arel.star.count.as('count'))
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count_arel = yield table, count_arel if block_given?
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total = exec_query(count_arel.to_sql).to_hash.first['count'].to_i
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return if total == 0
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end
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# Update in batches of 5% until we run out of any rows to update.
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batch_size = ((total / 100.0) * 5.0).ceil
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max_size = 1000
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# The upper limit is 1000 to ensure we don't lock too many rows. For
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# example, for "merge_requests" even 1% of the table is around 35 000
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# rows for GitLab.com.
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batch_size = max_size if batch_size > max_size
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start_arel = table.project(table[:id]).order(table[:id].asc).take(1)
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start_arel = yield table, start_arel if block_given?
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first_row = exec_query(start_arel.to_sql).to_hash.first
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# In case there are no rows but we didn't catch it in the estimated size:
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return unless first_row
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start_id = first_row['id'].to_i
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say "Migrating #{table_name}.#{column} (~#{total.to_i} rows)"
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started_time = Time.zone.now
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last_time = Time.zone.now
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migrated = 0
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loop do
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stop_row = nil
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suppress_messages do
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stop_arel = table.project(table[:id])
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.where(table[:id].gteq(start_id))
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.order(table[:id].asc)
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.take(1)
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.skip(batch_size)
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stop_arel = yield table, stop_arel if block_given?
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stop_row = exec_query(stop_arel.to_sql).to_hash.first
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update_arel = Arel::UpdateManager.new
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.table(table)
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.set([[table[column], value]])
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.where(table[:id].gteq(start_id))
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if stop_row
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stop_id = stop_row['id'].to_i
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start_id = stop_id
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update_arel = update_arel.where(table[:id].lt(stop_id))
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end
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update_arel = yield table, update_arel if block_given?
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execute(update_arel.to_sql)
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end
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migrated += batch_size
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if Time.zone.now - last_time > 1
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status = "Migrated #{migrated} rows"
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percentage = 100.0 * migrated / total
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status += " (~#{sprintf('%.2f', percentage)}%, "
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remaining_time = (100.0 - percentage) * (Time.zone.now - started_time) / percentage
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status += "#{(remaining_time / 60).to_i}:"
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status += sprintf('%02d', remaining_time.to_i % 60)
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status += ' remaining, '
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# Tell users not to interrupt if we're almost done.
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if remaining_time > 10
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status += 'safe to interrupt'
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else
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status += 'DO NOT interrupt'
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end
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status += ')'
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say status, true
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last_time = Time.zone.now
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end
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# There are no more rows left to update.
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break unless stop_row
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end
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end
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# Adds a column with a default value without locking an entire table.
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#
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# This method runs the following steps:
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#
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# 1. Add the column with a default value of NULL.
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# 2. Change the default value of the column to the specified value.
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# 3. Update all existing rows in batches.
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# 4. Set a `NOT NULL` constraint on the column if desired (the default).
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#
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# These steps ensure a column can be added to a large and commonly used
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# table without locking the entire table for the duration of the table
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# modification.
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#
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# table - The name of the table to update.
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# column - The name of the column to add.
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# type - The column type (e.g. `:integer`).
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# default - The default value for the column.
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# limit - Sets a column limit. For example, for :integer, the default is
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# 4-bytes. Set `limit: 8` to allow 8-byte integers.
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# allow_null - When set to `true` the column will allow NULL values, the
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# default is to not allow NULL values.
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#
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# This method can also take a block which is passed directly to the
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# `update_column_in_batches` method.
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def add_column_with_default(table, column, type, default:, limit: nil, allow_null: false, &block)
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if transaction_open?
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raise 'add_column_with_default can not be run inside a transaction, ' \
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'you can disable transactions by calling disable_ddl_transaction! ' \
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'in the body of your migration class'
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end
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disable_statement_timeout
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transaction do
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if limit
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add_column(table, column, type, default: nil, limit: limit)
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else
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add_column(table, column, type, default: nil)
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end
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# Changing the default before the update ensures any newly inserted
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# rows already use the proper default value.
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change_column_default(table, column, default)
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end
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begin
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update_column_in_batches(table, column, default, &block)
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change_column_null(table, column, false) unless allow_null
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# We want to rescue _all_ exceptions here, even those that don't inherit
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# from StandardError.
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rescue Exception => error # rubocop: disable all
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remove_column(table, column)
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raise error
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end
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end
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# Renames a column without requiring downtime.
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#
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# Concurrent renames work by using database triggers to ensure both the
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# old and new column are in sync. However, this method will _not_ remove
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# the triggers or the old column automatically; this needs to be done
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# manually in a post-deployment migration. This can be done using the
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# method `cleanup_concurrent_column_rename`.
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#
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# table - The name of the database table containing the column.
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# old - The old column name.
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# new - The new column name.
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# type - The type of the new column. If no type is given the old column's
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# type is used.
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def rename_column_concurrently(table, old, new, type: nil)
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if transaction_open?
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raise 'rename_column_concurrently can not be run inside a transaction'
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end
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check_trigger_permissions!(table)
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trigger_name = rename_trigger_name(table, old, new)
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# If we were in the middle of update_column_in_batches, we should remove
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# the old column and start over, as we have no idea where we were.
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if column_for(table, new)
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if MigrationHelpers.postgresql?
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remove_rename_triggers_for_postgresql(table, trigger_name)
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else
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remove_rename_triggers_for_mysql(trigger_name)
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end
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remove_column(table, new)
|
|
end
|
|
|
|
old_col = column_for(table, old)
|
|
new_type = type || old_col.type
|
|
|
|
col_opts = {
|
|
precision: old_col.precision,
|
|
scale: old_col.scale,
|
|
}
|
|
|
|
# We may be trying to reset the limit on an integer column type, so let
|
|
# Rails handle that.
|
|
unless [:bigint, :integer].include?(new_type)
|
|
col_opts[:limit] = old_col.limit
|
|
end
|
|
|
|
add_column(table, new, new_type, col_opts)
|
|
|
|
# We set the default value _after_ adding the column so we don't end up
|
|
# updating any existing data with the default value. This isn't
|
|
# necessary since we copy over old values further down.
|
|
change_column_default(table, new, old_col.default) if old_col.default
|
|
|
|
quoted_table = quote_table_name(table)
|
|
quoted_old = quote_column_name(old)
|
|
quoted_new = quote_column_name(new)
|
|
|
|
if MigrationHelpers.postgresql?
|
|
install_rename_triggers_for_postgresql(trigger_name, quoted_table,
|
|
quoted_old, quoted_new)
|
|
else
|
|
install_rename_triggers_for_mysql(trigger_name, quoted_table,
|
|
quoted_old, quoted_new)
|
|
end
|
|
|
|
update_column_in_batches(table, new, Arel::Table.new(table)[old])
|
|
|
|
change_column_null(table, new, false) unless old_col.null
|
|
|
|
copy_indexes(table, old, new)
|
|
copy_foreign_keys(table, old, new)
|
|
end
|
|
|
|
# Changes the type of a column concurrently.
|
|
#
|
|
# table - The table containing the column.
|
|
# column - The name of the column to change.
|
|
# new_type - The new column type.
|
|
def change_column_type_concurrently(table, column, new_type)
|
|
temp_column = rename_column_name(column)
|
|
|
|
rename_column_concurrently(table, column, temp_column, type: new_type)
|
|
|
|
# Primary keys don't necessarily have an associated index.
|
|
if ActiveRecord::Base.get_primary_key(table) == column.to_s
|
|
old_pk_index_name = "index_#{table}_on_#{column}"
|
|
new_pk_index_name = "index_#{table}_on_#{column}_cm"
|
|
|
|
unless indexes_for(table, column).find{|i| i.name == old_pk_index_name}
|
|
add_concurrent_index(table, [temp_column], {
|
|
unique: true,
|
|
name: new_pk_index_name
|
|
})
|
|
end
|
|
end
|
|
end
|
|
|
|
# Performs cleanup of a concurrent type change.
|
|
#
|
|
# table - The table containing the column.
|
|
# column - The name of the column to change.
|
|
# new_type - The new column type.
|
|
def cleanup_concurrent_column_type_change(table, column)
|
|
temp_column = rename_column_name(column)
|
|
|
|
# Wait for the indices to be built
|
|
indexes_for(table, column).each do |index|
|
|
expected_name = index.name + '_cm'
|
|
|
|
puts "Waiting for index #{expected_name}"
|
|
sleep 1 until indexes_for(table, temp_column).find {|i| i.name == expected_name }
|
|
end
|
|
|
|
was_primary = (ActiveRecord::Base.get_primary_key(table) == column.to_s)
|
|
old_default_fn = column_for(table, column).default_function
|
|
|
|
old_fks = []
|
|
if was_primary
|
|
# Get any foreign keys pointing at this column we need to recreate, and
|
|
# remove the old ones.
|
|
# Based on code from:
|
|
# http://errorbank.blogspot.com/2011/03/list-all-foreign-keys-references-for.html
|
|
old_fks_res = execute <<-EOF.strip_heredoc
|
|
select m.relname as src_table,
|
|
(select a.attname
|
|
from pg_attribute a
|
|
where a.attrelid = m.oid
|
|
and a.attnum = o.conkey[1]
|
|
and a.attisdropped = false) as src_col,
|
|
o.conname as name,
|
|
o.confdeltype as on_delete
|
|
from pg_constraint o
|
|
left join pg_class f on f.oid = o.confrelid
|
|
left join pg_class c on c.oid = o.conrelid
|
|
left join pg_class m on m.oid = o.conrelid
|
|
where o.contype = 'f'
|
|
and o.conrelid in (
|
|
select oid from pg_class c where c.relkind = 'r')
|
|
and f.relname = '#{table}';
|
|
EOF
|
|
old_fks = old_fks_res.to_a
|
|
old_fks.each do |old_fk|
|
|
add_concurrent_foreign_key(
|
|
old_fk['src_table'],
|
|
table,
|
|
column: old_fk['src_col'],
|
|
target_col: temp_column,
|
|
on_delete: extract_foreign_key_action(old_fk['on_delete'])
|
|
)
|
|
|
|
remove_foreign_key(old_fk['src_table'], name: old_fk['name'])
|
|
end
|
|
end
|
|
|
|
# If there was a sequence owned by the old column, make it owned by the
|
|
# new column, as it will otherwise be deleted when we get rid of the
|
|
# old column.
|
|
if (seq_match = /^nextval\('([^']*)'(::text|::regclass)?\)/.match(old_default_fn))
|
|
seq_name = seq_match[1]
|
|
execute("ALTER SEQUENCE #{seq_name} OWNED BY #{table}.#{temp_column}")
|
|
end
|
|
|
|
transaction do
|
|
# This has to be performed in a transaction as otherwise we might have
|
|
# inconsistent data.
|
|
|
|
cleanup_concurrent_column_rename(table, column, temp_column)
|
|
rename_column(table, temp_column, column)
|
|
|
|
# If there was an old default function, we didn't copy it. Do that now
|
|
# in the transaction, so we don't miss anything.
|
|
change_column_default(table, column, -> { old_default_fn }) if old_default_fn
|
|
end
|
|
|
|
# Rename any indices back to what they should be.
|
|
indexes_for(table, column).each do |index|
|
|
next unless index.name.end_with?('_cm')
|
|
|
|
real_index_name = index.name.sub(/_cm$/, '')
|
|
rename_index(table, index.name, real_index_name)
|
|
end
|
|
|
|
# Rename any foreign keys back to names based on the real column.
|
|
foreign_keys_for(table, column).each do |fk|
|
|
old_fk_name = concurrent_foreign_key_name(fk.from_table, temp_column, 'id')
|
|
new_fk_name = concurrent_foreign_key_name(fk.from_table, column, 'id')
|
|
execute("ALTER TABLE #{fk.from_table} RENAME CONSTRAINT " +
|
|
"#{old_fk_name} TO #{new_fk_name}")
|
|
end
|
|
|
|
# Rename any foreign keys from other tables to names based on the real
|
|
# column.
|
|
old_fks.each do |old_fk|
|
|
old_fk_name = concurrent_foreign_key_name(old_fk['src_table'],
|
|
old_fk['src_col'], temp_column)
|
|
new_fk_name = concurrent_foreign_key_name(old_fk['src_table'],
|
|
old_fk['src_col'], column)
|
|
execute("ALTER TABLE #{old_fk['src_table']} RENAME CONSTRAINT " +
|
|
"#{old_fk_name} TO #{new_fk_name}")
|
|
end
|
|
|
|
# If the old column was a primary key, mark the new one as a primary key.
|
|
if was_primary
|
|
execute("ALTER TABLE #{table} ADD PRIMARY KEY USING INDEX " +
|
|
"index_#{table}_on_#{column}")
|
|
end
|
|
end
|
|
|
|
# Cleans up a concurrent column name.
|
|
#
|
|
# This method takes care of removing previously installed triggers as well
|
|
# as removing the old column.
|
|
#
|
|
# table - The name of the database table.
|
|
# old - The name of the old column.
|
|
# new - The name of the new column.
|
|
def cleanup_concurrent_column_rename(table, old, new)
|
|
trigger_name = rename_trigger_name(table, old, new)
|
|
|
|
check_trigger_permissions!(table)
|
|
|
|
if MigrationHelpers.postgresql?
|
|
remove_rename_triggers_for_postgresql(table, trigger_name)
|
|
else
|
|
remove_rename_triggers_for_mysql(trigger_name)
|
|
end
|
|
|
|
remove_column(table, old)
|
|
end
|
|
|
|
# Performs a concurrent column rename when using PostgreSQL.
|
|
def install_rename_triggers_for_postgresql(trigger, table, old, new)
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE OR REPLACE FUNCTION #{trigger}()
|
|
RETURNS trigger AS
|
|
$BODY$
|
|
BEGIN
|
|
NEW.#{new} := NEW.#{old};
|
|
RETURN NEW;
|
|
END;
|
|
$BODY$
|
|
LANGUAGE 'plpgsql'
|
|
VOLATILE
|
|
EOF
|
|
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE TRIGGER #{trigger}
|
|
BEFORE INSERT OR UPDATE
|
|
ON #{table}
|
|
FOR EACH ROW
|
|
EXECUTE PROCEDURE #{trigger}()
|
|
EOF
|
|
end
|
|
|
|
# Installs the triggers necessary to perform a concurrent column rename on
|
|
# MySQL.
|
|
def install_rename_triggers_for_mysql(trigger, table, old, new)
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE TRIGGER #{trigger}_insert
|
|
BEFORE INSERT
|
|
ON #{table}
|
|
FOR EACH ROW
|
|
SET NEW.#{new} = NEW.#{old}
|
|
EOF
|
|
|
|
execute <<-EOF.strip_heredoc
|
|
CREATE TRIGGER #{trigger}_update
|
|
BEFORE UPDATE
|
|
ON #{table}
|
|
FOR EACH ROW
|
|
SET NEW.#{new} = NEW.#{old}
|
|
EOF
|
|
end
|
|
|
|
# Removes the triggers used for renaming a PostgreSQL column concurrently.
|
|
def remove_rename_triggers_for_postgresql(table, trigger)
|
|
execute("DROP TRIGGER IF EXISTS #{trigger} ON #{table}")
|
|
execute("DROP FUNCTION IF EXISTS #{trigger}()")
|
|
end
|
|
|
|
# Removes the triggers used for renaming a MySQL column concurrently.
|
|
def remove_rename_triggers_for_mysql(trigger)
|
|
execute("DROP TRIGGER IF EXISTS #{trigger}_insert")
|
|
execute("DROP TRIGGER IF EXISTS #{trigger}_update")
|
|
end
|
|
|
|
# Returns the (base) name to use for triggers when renaming columns.
|
|
def rename_trigger_name(table, old, new)
|
|
'trigger_' + Digest::SHA256.hexdigest("#{table}_#{old}_#{new}").first(12)
|
|
end
|
|
|
|
# Returns the name to use for temporary rename columns.
|
|
def rename_column_name(base)
|
|
base.to_s + '_cm'
|
|
end
|
|
|
|
# Returns an Array containing the indexes for the given column
|
|
def indexes_for(table, column)
|
|
column = column.to_s
|
|
|
|
indexes(table).select { |index| index.columns.include?(column) }
|
|
end
|
|
|
|
# Returns an Array containing the foreign keys for the given column.
|
|
def foreign_keys_for(table, column)
|
|
column = column.to_s
|
|
|
|
foreign_keys(table).select { |fk| fk.column == column }
|
|
end
|
|
|
|
# Copies all indexes for the old column to a new column.
|
|
#
|
|
# table - The table containing the columns and indexes.
|
|
# old - The old column.
|
|
# new - The new column.
|
|
def copy_indexes(table, old, new)
|
|
old = old.to_s
|
|
new = new.to_s
|
|
|
|
indexes_for(table, old).each do |index|
|
|
new_columns = index.columns.map do |column|
|
|
column == old ? new : column
|
|
end
|
|
|
|
# This is necessary as we can't properly rename indexes such as
|
|
# "ci_taggings_idx".
|
|
name = index.name + '_cm'
|
|
|
|
# If the order contained the old column, map it to the new one.
|
|
order = index.orders
|
|
if order.key?(old)
|
|
order[new] = order.delete(old)
|
|
end
|
|
|
|
options = {
|
|
unique: index.unique,
|
|
name: name,
|
|
length: index.lengths,
|
|
order: order
|
|
}
|
|
|
|
# These options are not supported by MySQL, so we only add them if
|
|
# they were previously set.
|
|
options[:using] = index.using if index.using
|
|
options[:where] = index.where if index.where
|
|
|
|
add_concurrent_index(table, new_columns, options)
|
|
end
|
|
end
|
|
|
|
# Copies all foreign keys for the old column to the new column.
|
|
#
|
|
# table - The table containing the columns and indexes.
|
|
# old - The old column.
|
|
# new - The new column.
|
|
def copy_foreign_keys(table, old, new)
|
|
foreign_keys_for(table, old).each do |fk|
|
|
add_concurrent_foreign_key(fk.from_table,
|
|
fk.to_table,
|
|
column: new,
|
|
on_delete: fk.on_delete)
|
|
end
|
|
end
|
|
|
|
# Returns the column for the given table and column name.
|
|
def column_for(table, name)
|
|
name = name.to_s
|
|
|
|
columns(table).find { |column| column.name == name }
|
|
end
|
|
|
|
# This will replace the first occurrence of a string in a column with
|
|
# the replacement
|
|
# On postgresql we can use `regexp_replace` for that.
|
|
# On mysql we find the location of the pattern, and overwrite it
|
|
# with the replacement
|
|
def replace_sql(column, pattern, replacement)
|
|
quoted_pattern = Arel::Nodes::Quoted.new(pattern.to_s)
|
|
quoted_replacement = Arel::Nodes::Quoted.new(replacement.to_s)
|
|
|
|
if MigrationHelpers.mysql?
|
|
locate = Arel::Nodes::NamedFunction
|
|
.new('locate', [quoted_pattern, column])
|
|
insert_in_place = Arel::Nodes::NamedFunction
|
|
.new('insert', [column, locate, pattern.size, quoted_replacement])
|
|
|
|
Arel::Nodes::SqlLiteral.new(insert_in_place.to_sql)
|
|
else
|
|
replace = Arel::Nodes::NamedFunction
|
|
.new("regexp_replace", [column, quoted_pattern, quoted_replacement])
|
|
Arel::Nodes::SqlLiteral.new(replace.to_sql)
|
|
end
|
|
end
|
|
|
|
def remove_foreign_key_without_error(*args)
|
|
remove_foreign_key(*args)
|
|
rescue ArgumentError
|
|
end
|
|
|
|
def sidekiq_queue_migrate(queue_from, to:)
|
|
while sidekiq_queue_length(queue_from) > 0
|
|
Sidekiq.redis do |conn|
|
|
conn.rpoplpush "queue:#{queue_from}", "queue:#{to}"
|
|
end
|
|
end
|
|
end
|
|
|
|
def sidekiq_queue_length(queue_name)
|
|
Sidekiq.redis do |conn|
|
|
conn.llen("queue:#{queue_name}")
|
|
end
|
|
end
|
|
|
|
def check_trigger_permissions!(table)
|
|
unless Grant.create_and_execute_trigger?(table)
|
|
dbname = ActiveRecord::Base.configurations[Rails.env]['database']
|
|
user = ActiveRecord::Base.configurations[Rails.env]['username'] || ENV['USER']
|
|
|
|
raise <<-EOF
|
|
Your database user is not allowed to create, drop, or execute triggers on the
|
|
table #{table}.
|
|
|
|
If you are using PostgreSQL you can solve this by logging in to the Mastodon
|
|
database (#{dbname}) using a super user and running:
|
|
|
|
ALTER USER #{user} WITH SUPERUSER
|
|
|
|
The query will grant the user super user permissions, ensuring you don't run
|
|
into similar problems in the future (e.g. when new tables are created).
|
|
EOF
|
|
end
|
|
end
|
|
|
|
# Bulk queues background migration jobs for an entire table, batched by ID range.
|
|
# "Bulk" meaning many jobs will be pushed at a time for efficiency.
|
|
# If you need a delay interval per job, then use `queue_background_migration_jobs_by_range_at_intervals`.
|
|
#
|
|
# model_class - The table being iterated over
|
|
# job_class_name - The background migration job class as a string
|
|
# batch_size - The maximum number of rows per job
|
|
#
|
|
# Example:
|
|
#
|
|
# class Route < ActiveRecord::Base
|
|
# include EachBatch
|
|
# self.table_name = 'routes'
|
|
# end
|
|
#
|
|
# bulk_queue_background_migration_jobs_by_range(Route, 'ProcessRoutes')
|
|
#
|
|
# Where the model_class includes EachBatch, and the background migration exists:
|
|
#
|
|
# class Gitlab::BackgroundMigration::ProcessRoutes
|
|
# def perform(start_id, end_id)
|
|
# # do something
|
|
# end
|
|
# end
|
|
def bulk_queue_background_migration_jobs_by_range(model_class, job_class_name, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE)
|
|
raise "#{model_class} does not have an ID to use for batch ranges" unless model_class.column_names.include?('id')
|
|
|
|
jobs = []
|
|
|
|
model_class.each_batch(of: batch_size) do |relation|
|
|
start_id, end_id = relation.pluck('MIN(id), MAX(id)').first
|
|
|
|
if jobs.length >= BACKGROUND_MIGRATION_JOB_BUFFER_SIZE
|
|
# Note: This code path generally only helps with many millions of rows
|
|
# We push multiple jobs at a time to reduce the time spent in
|
|
# Sidekiq/Redis operations. We're using this buffer based approach so we
|
|
# don't need to run additional queries for every range.
|
|
BackgroundMigrationWorker.perform_bulk(jobs)
|
|
jobs.clear
|
|
end
|
|
|
|
jobs << [job_class_name, [start_id, end_id]]
|
|
end
|
|
|
|
BackgroundMigrationWorker.perform_bulk(jobs) unless jobs.empty?
|
|
end
|
|
|
|
# Queues background migration jobs for an entire table, batched by ID range.
|
|
# Each job is scheduled with a `delay_interval` in between.
|
|
# If you use a small interval, then some jobs may run at the same time.
|
|
#
|
|
# model_class - The table being iterated over
|
|
# job_class_name - The background migration job class as a string
|
|
# delay_interval - The duration between each job's scheduled time (must respond to `to_f`)
|
|
# batch_size - The maximum number of rows per job
|
|
#
|
|
# Example:
|
|
#
|
|
# class Route < ActiveRecord::Base
|
|
# include EachBatch
|
|
# self.table_name = 'routes'
|
|
# end
|
|
#
|
|
# queue_background_migration_jobs_by_range_at_intervals(Route, 'ProcessRoutes', 1.minute)
|
|
#
|
|
# Where the model_class includes EachBatch, and the background migration exists:
|
|
#
|
|
# class Gitlab::BackgroundMigration::ProcessRoutes
|
|
# def perform(start_id, end_id)
|
|
# # do something
|
|
# end
|
|
# end
|
|
def queue_background_migration_jobs_by_range_at_intervals(model_class, job_class_name, delay_interval, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE)
|
|
raise "#{model_class} does not have an ID to use for batch ranges" unless model_class.column_names.include?('id')
|
|
|
|
model_class.each_batch(of: batch_size) do |relation, index|
|
|
start_id, end_id = relation.pluck('MIN(id), MAX(id)').first
|
|
|
|
# `BackgroundMigrationWorker.bulk_perform_in` schedules all jobs for
|
|
# the same time, which is not helpful in most cases where we wish to
|
|
# spread the work over time.
|
|
BackgroundMigrationWorker.perform_in(delay_interval * index, job_class_name, [start_id, end_id])
|
|
end
|
|
end
|
|
|
|
private
|
|
|
|
# https://github.com/rails/rails/blob/v5.2.0/activerecord/lib/active_record/connection_adapters/postgresql/schema_statements.rb#L678-L684
|
|
def extract_foreign_key_action(specifier)
|
|
case specifier
|
|
when 'c'; :cascade
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when 'n'; :nullify
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when 'r'; :restrict
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end
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end
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end
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end
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# rubocop:enable all
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