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module Gitlab
module Database
module MigrationHelpers
BACKGROUND_MIGRATION_BATCH_SIZE = 1000 # Number of rows to process per job
BACKGROUND_MIGRATION_JOB_BUFFER_SIZE = 1000 # Number of jobs to bulk queue at a time
blackst0ne
committed
# Adds `created_at` and `updated_at` columns with timezone information.
#
# This method is an improved version of Rails' built-in method `add_timestamps`.
#
# Available options are:
# default - The default value for the column.
# null - When set to `true` the column will allow NULL values.
# The default is to not allow NULL values.
def add_timestamps_with_timezone(table_name, options = {})
options[:null] = false if options[:null].nil?
[:created_at, :updated_at].each do |column_name|
if options[:default] && transaction_open?
raise '`add_timestamps_with_timezone` with default value cannot be run inside a transaction. ' \
'You can disable transactions by calling `disable_ddl_transaction!` ' \
'in the body of your migration class'
end
# If default value is presented, use `add_column_with_default` method instead.
if options[:default]
add_column_with_default(
table_name,
column_name,
:datetime_with_timezone,
default: options[:default],
allow_null: options[:null]
)
else
add_column(table_name, column_name, :datetime_with_timezone, options)
end
end
end
# Creates a new index, concurrently when supported
#
# On PostgreSQL this method creates an index concurrently, on MySQL this
# creates a regular index.
#
# Example:
#
# add_concurrent_index :users, :some_column
#
# See Rails' `add_index` for more info on the available arguments.
def add_concurrent_index(table_name, column_name, options = {})
if transaction_open?
raise 'add_concurrent_index can not be run inside a transaction, ' \
'you can disable transactions by calling disable_ddl_transaction! ' \
'in the body of your migration class'
end
if Database.postgresql?
options = options.merge({ algorithm: :concurrently })
if index_exists?(table_name, column_name, options)
Rails.logger.warn "Index not created because it already exists (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}"
return
end
disable_statement_timeout do
add_index(table_name, column_name, options)
end
# Removes an existed index, concurrently when supported
#
# On PostgreSQL this method removes an index concurrently.
#
# Example:
#
# remove_concurrent_index :users, :some_column
#
# See Rails' `remove_index` for more info on the available arguments.
def remove_concurrent_index(table_name, column_name, options = {})
if transaction_open?
raise 'remove_concurrent_index can not be run inside a transaction, ' \
'you can disable transactions by calling disable_ddl_transaction! ' \
'in the body of your migration class'
end
if supports_drop_index_concurrently?
options = options.merge({ algorithm: :concurrently })
end
unless index_exists?(table_name, column_name, options)
Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, column_name: #{column_name}"
return
end
disable_statement_timeout do
remove_index(table_name, options.merge({ column: column_name }))
end
# Removes an existing index, concurrently when supported
#
# On PostgreSQL this method removes an index concurrently.
#
# Example:
#
# remove_concurrent_index :users, "index_X_by_Y"
#
# See Rails' `remove_index` for more info on the available arguments.
def remove_concurrent_index_by_name(table_name, index_name, options = {})
if transaction_open?
raise 'remove_concurrent_index_by_name can not be run inside a transaction, ' \
'you can disable transactions by calling disable_ddl_transaction! ' \
'in the body of your migration class'
end
if supports_drop_index_concurrently?
options = options.merge({ algorithm: :concurrently })
end
unless index_exists_by_name?(table_name, index_name)
Rails.logger.warn "Index not removed because it does not exist (this may be due to an aborted migration or similar): table_name: #{table_name}, index_name: #{index_name}"
return
end
disable_statement_timeout do
remove_index(table_name, options.merge({ name: index_name }))
end
end
# Only available on Postgresql >= 9.2
def supports_drop_index_concurrently?
return false unless Database.postgresql?
version = select_one("SELECT current_setting('server_version_num') AS v")['v'].to_i
version >= 90200
end
# Adds a foreign key with only minimal locking on the tables involved.
#
# This method only requires minimal locking when using PostgreSQL. When
# using MySQL this method will use Rails' default `add_foreign_key`.
#
# source - The source 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".
def add_concurrent_foreign_key(source, target, column:, on_delete: :cascade)
# Transactions would result in ALTER TABLE locks being held for the
# duration of the transaction, defeating the purpose of this method.
if transaction_open?
raise 'add_concurrent_foreign_key can not be run inside a transaction'
end
# While MySQL does allow disabling of foreign keys it has no equivalent
# of PostgreSQL's "VALIDATE CONSTRAINT". As a result we'll just fall
# back to the normal foreign key procedure.
if Database.mysql?
if foreign_key_exists?(source, target, column: column)
Rails.logger.warn "Foreign key not created because it exists already " \
"(this may be due to an aborted migration or similar): " \
"source: #{source}, target: #{target}, column: #{column}"
return
end
return add_foreign_key(source, target,
column: column,
on_delete: on_delete)
else
on_delete = 'SET NULL' if on_delete == :nullify
key_name = concurrent_foreign_key_name(source, column)
unless foreign_key_exists?(source, target, column: column)
Rails.logger.warn "Foreign key not created because it exists already " \
"(this may be due to an aborted migration or similar): " \
"source: #{source}, target: #{target}, column: #{column}"
# Using NOT VALID allows us to create a key without immediately
# validating it. This means we keep the ALTER TABLE lock only for a
# short period of time. The key _is_ enforced for any newly created
# data.
execute <<-EOF.strip_heredoc
ALTER TABLE #{source}
ADD CONSTRAINT #{key_name}
FOREIGN KEY (#{column})
REFERENCES #{target} (id)
#{on_delete ? "ON DELETE #{on_delete.upcase}" : ''}
NOT VALID;
EOF
end
# Validate the existing constraint. This can potentially take a very
# long time to complete, but fortunately does not lock the source table
# while running.
#
# Note this is a no-op in case the constraint is VALID already
disable_statement_timeout do
execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{key_name};")
end
def foreign_key_exists?(source, target = nil, column: nil)
foreign_keys(source).any? do |key|
if column
key.options[:column].to_s == column.to_s
else
key.to_table.to_s == target.to_s
end
end
end
# Returns the name for a concurrent foreign key.
#
# PostgreSQL constraint names have a limit of 63 bytes. The logic used
# here is based on Rails' foreign_key_name() method, which unfortunately
# is private so we can't rely on it directly.
def concurrent_foreign_key_name(table, column)
"fk_#{Digest::SHA256.hexdigest("#{table}_#{column}_fk").first(10)}"
end
# Long-running migrations may take more than the timeout allowed by
# the database. Disable the session's statement timeout to ensure
# migrations don't get killed prematurely. (PostgreSQL only)
#
# There are two possible ways to disable the statement timeout:
#
# - Per transaction (this is the preferred and default mode)
# - Per connection (requires a cleanup after the execution)
#
# When using a per connection disable statement, code must be inside
# a block so we can automatically execute `RESET ALL` after block finishes
# otherwise the statement will still be disabled until connection is dropped
# or `RESET ALL` is executed
def disable_statement_timeout
# bypass disabled_statement logic when not using postgres, but still execute block when one is given
unless Database.postgresql?
if block_given?
yield
end
return
end
if block_given?
begin
execute('SET statement_timeout TO 0')
yield
ensure
execute('RESET ALL')
end
else
unless transaction_open?
raise <<~ERROR
Cannot call disable_statement_timeout() without a transaction open or outside of a transaction block.
If you don't want to use a transaction wrap your code in a block call:
disable_statement_timeout { # code that requires disabled statement here }
This will make sure statement_timeout is disabled before and reset after the block execution is finished.
ERROR
end
execute('SET LOCAL statement_timeout TO 0')
end
def true_value
Database.true_value
end
def false_value
Database.false_value
end
# Updates the value of a column in batches.
#
# This method updates the table in batches of 5% of the total row count.
# A `batch_size` option can also be passed to set this to a fixed number.
# This method will continue updating rows until no rows remain.
#
# When given a block this method will yield two values to the block:
#
# 1. An instance of `Arel::Table` for the table that is being updated.
# 2. The query to run as an Arel object.
#
# By supplying a block one can add extra conditions to the queries being
# executed. Note that the same block is used for _all_ queries.
#
# Example:
#
# update_column_in_batches(:projects, :foo, 10) do |table, query|
# query.where(table[:some_column].eq('hello'))
# end
#
# This would result in this method updating only rows where
# `projects.some_column` equals "hello".
#
# table - The name of the table.
# column - The name of the column to update.
# value - The value for the column.
# The `value` argument is typically a literal. To perform a computed
# update, an Arel literal can be used instead:
#
# update_value = Arel.sql('bar * baz')
#
# update_column_in_batches(:projects, :foo, update_value) do |table, query|
# query.where(table[:some_column].eq('hello'))
# end
#
# Rubocop's Metrics/AbcSize metric is disabled for this method as Rubocop
# determines this method to be too complex while there's no way to make it
# less "complex" without introducing extra methods (which actually will
# make things _more_ complex).
#
# rubocop: disable Metrics/AbcSize
def update_column_in_batches(table, column, value, batch_size: nil)
if transaction_open?
raise 'update_column_in_batches can not be run inside a transaction, ' \
'you can disable transactions by calling disable_ddl_transaction! ' \
'in the body of your migration class'
end
table = Arel::Table.new(table)
count_arel = table.project(Arel.star.count.as('count'))
count_arel = yield table, count_arel if block_given?
total = exec_query(count_arel.to_sql).to_hash.first['count'].to_i
return if total == 0
if batch_size.nil?
# Update in batches of 5% until we run out of any rows to update.
batch_size = ((total / 100.0) * 5.0).ceil
max_size = 1000
# The upper limit is 1000 to ensure we don't lock too many rows. For
# example, for "merge_requests" even 1% of the table is around 35 000
# rows for GitLab.com.
batch_size = max_size if batch_size > max_size
end
start_arel = table.project(table[:id]).order(table[:id].asc).take(1)
start_arel = yield table, start_arel if block_given?
start_id = exec_query(start_arel.to_sql).to_hash.first['id'].to_i
stop_arel = table.project(table[:id])
.where(table[:id].gteq(start_id))
.order(table[:id].asc)
.take(1)
.skip(batch_size)
stop_arel = yield table, stop_arel if block_given?
stop_row = exec_query(stop_arel.to_sql).to_hash.first
.table(table)
.set([[table[column], value]])
.where(table[:id].gteq(start_id))
stop_id = stop_row['id'].to_i
start_id = stop_id
update_arel = update_arel.where(table[:id].lt(stop_id))
update_arel = yield table, update_arel if block_given?
execute(update_arel.to_sql)
# There are no more rows left to update.
break unless stop_row
end
end
# Adds a column with a default value without locking an entire table.
#
# This method runs the following steps:
#
# 1. Add the column with a default value of NULL.
# 2. Change the default value of the column to the specified value.
# 3. Update all existing rows in batches.
# 4. Set a `NOT NULL` constraint on the column if desired (the default).
#
# These steps ensure a column can be added to a large and commonly used
# table without locking the entire table for the duration of the table
# modification.
#
# table - The name of the table to update.
# column - The name of the column to add.
# type - The column type (e.g. `:integer`).
# default - The default value for the column.
# limit - Sets a column limit. For example, for :integer, the default is
# 4-bytes. Set `limit: 8` to allow 8-byte integers.
# allow_null - When set to `true` the column will allow NULL values, the
# default is to not allow NULL values.
#
# This method can also take a block which is passed directly to the
# `update_column_in_batches` method.
def add_column_with_default(table, column, type, default:, limit: nil, allow_null: false, &block)
if transaction_open?
raise 'add_column_with_default can not be run inside a transaction, ' \
'you can disable transactions by calling disable_ddl_transaction! ' \
'in the body of your migration class'
end
disable_statement_timeout do
transaction do
if limit
add_column(table, column, type, default: nil, limit: limit)
else
add_column(table, column, type, default: nil)
end
# Changing the default before the update ensures any newly inserted
# rows already use the proper default value.
change_column_default(table, column, default)
begin
update_column_in_batches(table, column, default, &block)
change_column_null(table, column, false) unless allow_null
# We want to rescue _all_ exceptions here, even those that don't inherit
# from StandardError.
rescue Exception => error # rubocop: disable all
remove_column(table, column)
raise error
end
# Renames a column without requiring downtime.
#
# Concurrent renames work by using database triggers to ensure both the
# old and new column are in sync. However, this method will _not_ remove
# the triggers or the old column automatically; this needs to be done
# manually in a post-deployment migration. This can be done using the
# method `cleanup_concurrent_column_rename`.
#
# table - The name of the database table containing the column.
# old - The old column name.
# new - The new column name.
# type - The type of the new column. If no type is given the old column's
# type is used.
def rename_column_concurrently(table, old, new, type: nil)
if transaction_open?
raise 'rename_column_concurrently can not be run inside a transaction'
end
check_trigger_permissions!(table)
old_col = column_for(table, old)
new_type = type || old_col.type
add_column(table, new, new_type,
limit: old_col.limit,
precision: old_col.precision,
scale: old_col.scale)
# 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
install_rename_triggers(table, old, new)
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
# Installs triggers in a table that keep a new column in sync with an old
# one.
#
# table - The name of the table to install the trigger in.
# old_column - The name of the old column.
# new_column - The name of the new column.
def install_rename_triggers(table, old_column, new_column)
trigger_name = rename_trigger_name(table, old_column, new_column)
quoted_table = quote_table_name(table)
quoted_old = quote_column_name(old_column)
quoted_new = quote_column_name(new_column)
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if Database.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
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 = "#{column}_for_type_change"
rename_column_concurrently(table, column, temp_column, type: new_type)
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 = "#{column}_for_type_change"
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)
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 Database.postgresql?
remove_rename_triggers_for_postgresql(table, trigger_name)
else
remove_rename_triggers_for_mysql(trigger_name)
end
remove_column(table, old)
end
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# Changes the column type of a table using a background migration.
#
# Because this method uses a background migration it's more suitable for
# large tables. For small tables it's better to use
# `change_column_type_concurrently` since it can complete its work in a
# much shorter amount of time and doesn't rely on Sidekiq.
#
# Example usage:
#
# class Issue < ActiveRecord::Base
# self.table_name = 'issues'
#
# include EachBatch
#
# def self.to_migrate
# where('closed_at IS NOT NULL')
# end
# end
#
# change_column_type_using_background_migration(
# Issue.to_migrate,
# :closed_at,
# :datetime_with_timezone
# )
#
# Reverting a migration like this is done exactly the same way, just with
# a different type to migrate to (e.g. `:datetime` in the above example).
#
# relation - An ActiveRecord relation to use for scheduling jobs and
# figuring out what table we're modifying. This relation _must_
# have the EachBatch module included.
#
# column - The name of the column for which the type will be changed.
#
# new_type - The new type of the column.
#
# batch_size - The number of rows to schedule in a single background
# migration.
#
# interval - The time interval between every background migration.
def change_column_type_using_background_migration(
relation,
column,
new_type,
batch_size: 10_000,
interval: 10.minutes
)
unless relation.model < EachBatch
raise TypeError, 'The relation must include the EachBatch module'
end
temp_column = "#{column}_for_type_change"
table = relation.table_name
max_index = 0
add_column(table, temp_column, new_type)
install_rename_triggers(table, column, temp_column)
# Schedule the jobs that will copy the data from the old column to the
# new one. Rows with NULL values in our source column are skipped since
# the target column is already NULL at this point.
relation.where.not(column => nil).each_batch(of: batch_size) do |batch, index|
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start_id, end_id = batch.pluck('MIN(id), MAX(id)').first
max_index = index
BackgroundMigrationWorker.perform_in(
index * interval,
'CopyColumn',
[table, column, temp_column, start_id, end_id]
)
end
# Schedule the renaming of the column to happen (initially) 1 hour after
# the last batch finished.
BackgroundMigrationWorker.perform_in(
(max_index * interval) + 1.hour,
'CleanupConcurrentTypeChange',
[table, column, temp_column]
)
if perform_background_migration_inline?
# To ensure the schema is up to date immediately we perform the
# migration inline in dev / test environments.
Gitlab::BackgroundMigration.steal('CopyColumn')
Gitlab::BackgroundMigration.steal('CleanupConcurrentTypeChange')
end
end
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# Renames a column using a background migration.
#
# Because this method uses a background migration it's more suitable for
# large tables. For small tables it's better to use
# `rename_column_concurrently` since it can complete its work in a much
# shorter amount of time and doesn't rely on Sidekiq.
#
# Example usage:
#
# rename_column_using_background_migration(
# :users,
# :feed_token,
# :rss_token
# )
#
# table - The name of the database table containing the column.
#
# old - The old column name.
#
# new - The new column name.
#
# type - The type of the new column. If no type is given the old column's
# type is used.
#
# batch_size - The number of rows to schedule in a single background
# migration.
#
# interval - The time interval between every background migration.
def rename_column_using_background_migration(
table,
old_column,
new_column,
type: nil,
batch_size: 10_000,
interval: 10.minutes
)
check_trigger_permissions!(table)
old_col = column_for(table, old_column)
new_type = type || old_col.type
max_index = 0
add_column(table, new_column, new_type,
limit: old_col.limit,
precision: old_col.precision,
scale: old_col.scale)
# 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_column, old_col.default) if old_col.default
install_rename_triggers(table, old_column, new_column)
model = Class.new(ActiveRecord::Base) do
self.table_name = table
include ::EachBatch
end
# Schedule the jobs that will copy the data from the old column to the
# new one. Rows with NULL values in our source column are skipped since
# the target column is already NULL at this point.
model.where.not(old_column => nil).each_batch(of: batch_size) do |batch, index|
start_id, end_id = batch.pluck('MIN(id), MAX(id)').first
max_index = index
BackgroundMigrationWorker.perform_in(
index * interval,
'CopyColumn',
[table, old_column, new_column, start_id, end_id]
)
end
# Schedule the renaming of the column to happen (initially) 1 hour after
# the last batch finished.
BackgroundMigrationWorker.perform_in(
(max_index * interval) + 1.hour,
'CleanupConcurrentRename',
[table, old_column, new_column]
)
if perform_background_migration_inline?
# To ensure the schema is up to date immediately we perform the
# migration inline in dev / test environments.
Gitlab::BackgroundMigration.steal('CopyColumn')
Gitlab::BackgroundMigration.steal('CleanupConcurrentRename')
end
end
def perform_background_migration_inline?
Rails.env.test? || Rails.env.development?
end
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# 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")
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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 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".
unless index.name.include?(old)
raise "The index #{index.name} can not be copied as it does not "\
"mention the old column. You have to rename this index manually first."
end
name = index.name.gsub(old, new)
options = {
unique: index.unique,
name: name,
length: index.lengths,
order: index.orders
}
# 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
unless index.opclasses.blank?
opclasses = index.opclasses.dup
# Copy the operator classes for the old column (if any) to the new
# column.
opclasses[new] = opclasses.delete(old) if opclasses[old]
options[:opclasses] = opclasses
end
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 Database.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_if_exists(*args)
if foreign_key_exists?(*args)
remove_foreign_key(*args)
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 = Database.database_name
user = Database.username
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 GitLab
database (#{dbname}) using a super user and running:
ALTER #{user} WITH SUPERUSER
For MySQL you instead need to run:
GRANT ALL PRIVILEGES ON #{dbname}.* TO #{user}@'%'
Both queries 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 = []
table_name = model_class.quoted_table_name
model_class.each_batch(of: batch_size) do |relation|
start_id, end_id = relation.pluck("MIN(#{table_name}.id), MAX(#{table_name}.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.bulk_perform_async(jobs)
jobs.clear
end
jobs << [job_class_name, [start_id, end_id]]
end