1363 lines
		
	
	
		
			54 KiB
		
	
	
	
		
			Ruby
		
	
	
	
			
		
		
	
	
			1363 lines
		
	
	
		
			54 KiB
		
	
	
	
		
			Ruby
		
	
	
	
# frozen_string_literal: true
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module Gitlab
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  module Database
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    module MigrationHelpers
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      include Migrations::ReestablishedConnectionStack
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      include Migrations::BackgroundMigrationHelpers
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      include Migrations::BatchedBackgroundMigrationHelpers
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      include Migrations::LockRetriesHelpers
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      include Migrations::TimeoutHelpers
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      include Migrations::ConstraintsHelpers
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      include Migrations::ExtensionHelpers
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      include Migrations::SidekiqHelpers
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      include Migrations::RedisHelpers
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      include DynamicModelHelpers
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      include RenameTableHelpers
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      include AsyncIndexes::MigrationHelpers
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      include AsyncConstraints::MigrationHelpers
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      include WraparoundVacuumHelpers
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      def define_batchable_model(table_name, connection: self.connection, primary_key: nil)
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        super(table_name, connection: connection, primary_key: primary_key)
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      end
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      def each_batch(table_name, connection: self.connection, **kwargs)
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        super(table_name, connection: connection, **kwargs)
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      end
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      def each_batch_range(table_name, connection: self.connection, **kwargs)
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        super(table_name, connection: connection, **kwargs)
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      end
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      DEFAULT_TIMESTAMP_COLUMNS = %i[created_at updated_at].freeze
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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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      # By default, adds `created_at` and `updated_at` columns, but these can be specified as:
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      #
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      #   add_timestamps_with_timezone(:my_table, columns: [:created_at, :deleted_at])
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      #
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      # This allows you to create just the timestamps you need, saving space.
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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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      #  :columns - the column names to create. Must end with `_at`.
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      #             Default value: `DEFAULT_TIMESTAMP_COLUMNS`
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      #
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      # All options are optional.
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      def add_timestamps_with_timezone(table_name, options = {})
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        columns = options.fetch(:columns, DEFAULT_TIMESTAMP_COLUMNS)
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        columns.each do |column_name|
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          validate_timestamp_column_name!(column_name)
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          add_column(
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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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            null: options[:null] || false
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          )
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        end
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      end
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      # To be used in the `#down` method of migrations that
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      # use `#add_timestamps_with_timezone`.
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      #
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      # Available options are:
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      #  :columns - the column names to remove. Must be one
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      #             Default value: `DEFAULT_TIMESTAMP_COLUMNS`
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      #
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      # All options are optional.
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      def remove_timestamps(table_name, options = {})
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        columns = options.fetch(:columns, DEFAULT_TIMESTAMP_COLUMNS)
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        columns.each do |column_name|
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          remove_column(table_name, column_name)
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        end
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      end
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      # Creates a new index, concurrently
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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 !options.delete(:allow_partition) && partition?(table_name)
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          raise ArgumentError, 'add_concurrent_index can not be used on a partitioned '  \
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            'table. Please use add_concurrent_partitioned_index on the partitioned table ' \
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            'as we need to create indexes on each partition and an index on the parent table'
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        end
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        options = options.merge({ algorithm: :concurrently })
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        if index_exists?(table_name, column_name, **options)
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          name = options[:name] || index_name(table_name, column_name)
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          _, schema = table_name.to_s.split('.').reverse
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          if index_invalid?(name, schema: schema)
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            say "Index being recreated because the existing version was INVALID: table_name: #{table_name}, column_name: #{column_name}"
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            remove_concurrent_index_by_name(table_name, name)
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          else
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            say "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}"
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            return
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          end
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        end
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        disable_statement_timeout do
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          add_index(table_name, column_name, **options)
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        end
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        # We created this index. Now let's remove the queuing entry for async creation in case it's still there.
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        unprepare_async_index(table_name, column_name, **options)
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      end
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      def index_invalid?(index_name, schema: nil)
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        index_name = connection.quote(index_name)
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        schema = connection.quote(schema) if schema
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        schema ||= 'current_schema()'
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        connection.select_value(<<~SQL)
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          select not i.indisvalid
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          from pg_class c
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          inner join pg_index i
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            on c.oid = i.indexrelid
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          inner join pg_namespace n
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            on n.oid = c.relnamespace
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          where n.nspname = #{schema}
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            and c.relname = #{index_name}
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        SQL
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      end
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      # Removes an existed 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 partition?(table_name)
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          raise ArgumentError, 'remove_concurrent_index can not be used on a partitioned '  \
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            'table. Please use remove_concurrent_partitioned_index_by_name on the partitioned table ' \
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            'as we need to remove the index on the parent table'
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        end
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        options = options.merge({ algorithm: :concurrently })
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        unless index_exists?(table_name, column_name, **options)
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          Gitlab::AppLogger.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}"
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          return
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        end
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        disable_statement_timeout do
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          remove_index(table_name, **options.merge({ column: column_name }))
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        end
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        # We removed this index. Now let's make sure it's not queued for async creation.
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        unprepare_async_index(table_name, column_name, **options)
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      end
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      # Removes an existing 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 partition?(table_name)
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          raise ArgumentError, 'remove_concurrent_index_by_name can not be used on a partitioned '  \
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            'table. Please use remove_concurrent_partitioned_index_by_name on the partitioned table ' \
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            'as we need to remove the index on the parent table'
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        end
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        index_name = index_name[:name] if index_name.is_a?(Hash)
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        raise 'remove_concurrent_index_by_name must get an index name as the second argument' if index_name.blank?
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        options = options.merge({ algorithm: :concurrently })
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        unless index_exists_by_name?(table_name, index_name)
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          Gitlab::AppLogger.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}"
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          return
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        end
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        disable_statement_timeout do
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          remove_index(table_name, **options.merge({ name: index_name }))
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        end
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        # We removed this index. Now let's make sure it's not queued for async creation.
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        unprepare_async_index_by_name(table_name, index_name, **options)
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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
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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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      # target_column - The name of the referenced column, defaults to "id".
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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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      # on_update - The action to perform when associated data is updated,
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      #             defaults to nil. This is useful for multi column FKs if
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      #             it's desirable to update one of the columns.
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      # name - The name of the foreign key.
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      # validate - Flag that controls whether the new foreign key will be validated after creation.
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      #            If the flag is not set, the constraint will only be enforced for new data.
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      # reverse_lock_order - Flag that controls whether we should attempt to acquire locks in the reverse
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      #                      order of the ALTER TABLE. This can be useful in situations where the foreign
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      #                      key creation could deadlock with another process.
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      #
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      def add_concurrent_foreign_key(source, target, column:, **options)
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        options.reverse_merge!({
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          on_delete: :cascade,
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          on_update: nil,
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          target_column: :id,
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          validate: true,
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          reverse_lock_order: false,
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          allow_partitioned: false,
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          column: column
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        })
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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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        if !options.delete(:allow_partitioned) && table_partitioned?(source)
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          raise ArgumentError, 'add_concurrent_foreign_key can not be used on a partitioned ' \
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            'table. Please use add_concurrent_partitioned_foreign_key on the partitioned table ' \
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            'as we need to create foreign keys on each partition and a FK on the parent table'
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        end
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        options[:name] ||= concurrent_foreign_key_name(source, column)
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        options[:primary_key] = options[:target_column]
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        check_options = options.slice(:column, :on_delete, :on_update, :name, :primary_key)
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        if foreign_key_exists?(source, target, **check_options)
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          warning_message = "Foreign key not created because it exists already " \
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            "(this may be due to an aborted migration or similar): " \
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            "source: #{source}, target: #{target}, column: #{options[:column]}, "\
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            "name: #{options[:name]}, on_update: #{options[:on_update]}, "\
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            "on_delete: #{options[:on_delete]}"
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          Gitlab::AppLogger.warn warning_message
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        else
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          execute_add_concurrent_foreign_key(source, target, options)
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        end
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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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        # Disable this check by passing `validate: false` to the method call
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        # The check will be enforced for new data (inserts) coming in,
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        # but validating existing data is delayed.
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        #
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        # Note this is a no-op in case the constraint is VALID already
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        if options[:validate]
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          disable_statement_timeout do
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            execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{options[:name]};")
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          end
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        end
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      end
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      def validate_foreign_key(source, column, name: nil)
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        fk_name = name || concurrent_foreign_key_name(source, column)
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        unless foreign_key_exists?(source, name: fk_name)
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          raise missing_schema_object_message(source, "foreign key", fk_name)
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        end
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        disable_statement_timeout do
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          execute("ALTER TABLE #{source} VALIDATE CONSTRAINT #{fk_name};")
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        end
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      end
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      def foreign_key_exists?(source, target = nil, **options)
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        # This if block is necessary because foreign_key_exists? is called in down migrations that may execute before
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        # the postgres_foreign_keys view had necessary columns added.
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        # In that case, we revert to the previous behavior of this method.
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        # The behavior in the if block has a bug: it always returns false if the fk being checked has multiple columns.
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        # This can be removed after init_schema.rb passes 20221122210711_add_columns_to_postgres_foreign_keys.rb
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        # Tracking issue: https://gitlab.com/gitlab-org/gitlab/-/issues/386796
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        unless connection.column_exists?('postgres_foreign_keys', 'constrained_table_name')
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          return foreign_keys(source).any? do |foreign_key|
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            tables_match?(target.to_s, foreign_key.to_table.to_s) &&
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                options_match?(foreign_key.options, options)
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          end
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        end
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        # Since we may be migrating in one go from a previous version without
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        # `constrained_table_name` then we may see that this column exists
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        # (as above) but the schema cache is still outdated for the model.
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        unless Gitlab::Database::PostgresForeignKey.column_names.include?('constrained_table_name')
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          Gitlab::Database::PostgresForeignKey.reset_column_information
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        end
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        fks = Gitlab::Database::PostgresForeignKey.by_constrained_table_name_or_identifier(source)
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        fks = fks.by_referenced_table_name(target) if target
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        fks = fks.by_name(options[:name]) if options[:name]
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        fks = fks.by_constrained_columns(options[:column]) if options[:column]
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        fks = fks.by_referenced_columns(options[:primary_key]) if options[:primary_key]
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        fks = fks.by_on_delete_action(options[:on_delete]) if options[:on_delete]
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        fks.exists?
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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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      #
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      # prefix:
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      # - The default prefix is `fk_` for backward compatibility with the existing
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      # concurrent foreign key helpers.
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      # - For standard rails foreign keys the prefix is `fk_rails_`
 | 
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      #
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      def concurrent_foreign_key_name(table, column, prefix: 'fk_')
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        identifier = "#{table}_#{multiple_columns(column, separator: '_')}_fk"
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        hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
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        "#{prefix}#{hashed_identifier}"
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      end
 | 
						|
 | 
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      def true_value
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        Database.true_value
 | 
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      end
 | 
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 | 
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      def false_value
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        Database.false_value
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      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.
 | 
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      # This method will continue updating rows until no rows remain.
 | 
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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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      #
 | 
						|
      # 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.
 | 
						|
      # column - The name of the column to update.
 | 
						|
      # value - The value for the column.
 | 
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      #
 | 
						|
      # The `value` argument is typically a literal. To perform a computed
 | 
						|
      # update, an Arel literal can be used instead:
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      #
 | 
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      #     update_value = Arel.sql('bar * baz')
 | 
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      #
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      #     update_column_in_batches(:projects, :foo, update_value) do |table, query|
 | 
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      #       query.where(table[:some_column].eq('hello'))
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      #     end
 | 
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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
 | 
						|
      # less "complex" without introducing extra methods (which actually will
 | 
						|
      # make things _more_ complex).
 | 
						|
      #
 | 
						|
      # `batch_column_name` option is for tables without primary key, in this
 | 
						|
      # case another unique integer column can be used. Example: :user_id
 | 
						|
      #
 | 
						|
      # rubocop: disable Metrics/AbcSize
 | 
						|
      def update_column_in_batches(table_name, column, value, batch_size: nil, batch_column_name: :id, disable_lock_writes: false)
 | 
						|
        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_name)
 | 
						|
 | 
						|
        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_a.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[batch_column_name]).order(table[batch_column_name].asc).take(1)
 | 
						|
        start_arel = yield table, start_arel if block_given?
 | 
						|
        start_id = exec_query(start_arel.to_sql).to_a.first[batch_column_name.to_s].to_i
 | 
						|
 | 
						|
        loop do
 | 
						|
          stop_arel = table.project(table[batch_column_name])
 | 
						|
            .where(table[batch_column_name].gteq(start_id))
 | 
						|
            .order(table[batch_column_name].asc)
 | 
						|
            .take(1)
 | 
						|
            .skip(batch_size)
 | 
						|
 | 
						|
          stop_arel = yield table, stop_arel if block_given?
 | 
						|
          stop_row = exec_query(stop_arel.to_sql).to_a.first
 | 
						|
 | 
						|
          update_arel = Arel::UpdateManager.new
 | 
						|
            .table(table)
 | 
						|
            .set([[table[column], value]])
 | 
						|
            .where(table[batch_column_name].gteq(start_id))
 | 
						|
 | 
						|
          if stop_row
 | 
						|
            stop_id = stop_row[batch_column_name.to_s].to_i
 | 
						|
            start_id = stop_id
 | 
						|
            update_arel = update_arel.where(table[batch_column_name].lt(stop_id))
 | 
						|
          end
 | 
						|
 | 
						|
          update_arel = yield table, update_arel if block_given?
 | 
						|
 | 
						|
          transaction do
 | 
						|
            execute("SELECT set_config('lock_writes.#{table_name}', 'false', true)") if disable_lock_writes
 | 
						|
            execute(update_arel.to_sql)
 | 
						|
          end
 | 
						|
 | 
						|
          # There are no more rows left to update.
 | 
						|
          break unless stop_row
 | 
						|
        end
 | 
						|
      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.
 | 
						|
      # batch_column_name - option is for tables without primary key, in this
 | 
						|
      #        case another unique integer column can be used. Example: :user_id
 | 
						|
      def rename_column_concurrently(table, old, new, type: nil, type_cast_function: nil, batch_column_name: :id)
 | 
						|
        unless column_exists?(table, batch_column_name)
 | 
						|
          raise "Column #{batch_column_name} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        if transaction_open?
 | 
						|
          raise 'rename_column_concurrently can not be run inside a transaction'
 | 
						|
        end
 | 
						|
 | 
						|
        check_trigger_permissions!(table)
 | 
						|
 | 
						|
        create_column_from(table, old, new, type: type, batch_column_name: batch_column_name, type_cast_function: type_cast_function)
 | 
						|
 | 
						|
        install_rename_triggers(table, old, new)
 | 
						|
      end
 | 
						|
 | 
						|
      # Reverses operations performed by rename_column_concurrently.
 | 
						|
      #
 | 
						|
      # This method takes care of removing previously installed triggers as well
 | 
						|
      # as removing the new column.
 | 
						|
      #
 | 
						|
      # table - The name of the database table.
 | 
						|
      # old - The name of the old column.
 | 
						|
      # new - The name of the new column.
 | 
						|
      def undo_rename_column_concurrently(table, old, new)
 | 
						|
        trigger_name = rename_trigger_name(table, old, new)
 | 
						|
 | 
						|
        check_trigger_permissions!(table)
 | 
						|
 | 
						|
        remove_rename_triggers(table, trigger_name)
 | 
						|
 | 
						|
        remove_column(table, 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.
 | 
						|
      # trigger_name - The name of the trigger to use (optional).
 | 
						|
      def install_rename_triggers(table, old, new, trigger_name: nil)
 | 
						|
        Gitlab::Database::UnidirectionalCopyTrigger.on_table(table, connection: connection).create(old, new, trigger_name: trigger_name)
 | 
						|
      end
 | 
						|
 | 
						|
      # Removes the triggers used for renaming a column concurrently.
 | 
						|
      def remove_rename_triggers(table, trigger)
 | 
						|
        Gitlab::Database::UnidirectionalCopyTrigger.on_table(table, connection: connection).drop(trigger)
 | 
						|
      end
 | 
						|
 | 
						|
      # Returns the (base) name to use for triggers when renaming columns.
 | 
						|
      def rename_trigger_name(table, old, new)
 | 
						|
        Gitlab::Database::UnidirectionalCopyTrigger.on_table(table, connection: connection).name(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, type_cast_function: nil, batch_column_name: :id)
 | 
						|
        temp_column = "#{column}_for_type_change"
 | 
						|
 | 
						|
        rename_column_concurrently(table, column, temp_column, type: new_type, type_cast_function: type_cast_function, batch_column_name: batch_column_name)
 | 
						|
      end
 | 
						|
 | 
						|
      # Reverses operations performed by change_column_type_concurrently.
 | 
						|
      #
 | 
						|
      # table - The table containing the column.
 | 
						|
      # column - The name of the column to change.
 | 
						|
      def undo_change_column_type_concurrently(table, column)
 | 
						|
        temp_column = "#{column}_for_type_change"
 | 
						|
 | 
						|
        undo_rename_column_concurrently(table, column, temp_column)
 | 
						|
      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: nil)
 | 
						|
        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
 | 
						|
 | 
						|
      # Reverses operations performed by cleanup_concurrent_column_type_change.
 | 
						|
      #
 | 
						|
      # table - The table containing the column.
 | 
						|
      # column - The name of the column to change.
 | 
						|
      # old_type - The type of the original column used with change_column_type_concurrently.
 | 
						|
      # type_cast_function - Required if the conversion back to the original type is not automatic
 | 
						|
      # batch_column_name - option for tables without a primary key, in this case
 | 
						|
      #            another unique integer column can be used. Example: :user_id
 | 
						|
      def undo_cleanup_concurrent_column_type_change(table, column, old_type, type_cast_function: nil, batch_column_name: :id, limit: nil, temp_column: nil)
 | 
						|
        Gitlab::Database::QueryAnalyzers::RestrictAllowedSchemas.require_ddl_mode!
 | 
						|
 | 
						|
        temp_column ||= "#{column}_for_type_change"
 | 
						|
 | 
						|
        # Using a descriptive name that includes orinal column's name risks
 | 
						|
        # taking us above the 63 character limit, so we use a hash
 | 
						|
        identifier = "#{table}_#{column}_for_type_change"
 | 
						|
        hashed_identifier = Digest::SHA256.hexdigest(identifier).first(10)
 | 
						|
        temp_undo_cleanup_column = "tmp_undo_cleanup_column_#{hashed_identifier}"
 | 
						|
 | 
						|
        unless column_exists?(table, batch_column_name)
 | 
						|
          raise "Column #{batch_column_name} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        if transaction_open?
 | 
						|
          raise 'undo_cleanup_concurrent_column_type_change can not be run inside a transaction'
 | 
						|
        end
 | 
						|
 | 
						|
        check_trigger_permissions!(table)
 | 
						|
 | 
						|
        begin
 | 
						|
          create_column_from(
 | 
						|
            table,
 | 
						|
            column,
 | 
						|
            temp_undo_cleanup_column,
 | 
						|
            type: old_type,
 | 
						|
            batch_column_name: batch_column_name,
 | 
						|
            type_cast_function: type_cast_function,
 | 
						|
            limit: limit
 | 
						|
          )
 | 
						|
 | 
						|
          transaction do
 | 
						|
            # This has to be performed in a transaction as otherwise we might
 | 
						|
            # have inconsistent data.
 | 
						|
            rename_column(table, column, temp_column)
 | 
						|
            rename_column(table, temp_undo_cleanup_column, column)
 | 
						|
 | 
						|
            install_rename_triggers(table, column, temp_column)
 | 
						|
          end
 | 
						|
        rescue StandardError
 | 
						|
          # create_column_from can not run inside a transaction, which means
 | 
						|
          #  that there is a risk that if any of the operations that follow it
 | 
						|
          #  fail, we'll be left with an inconsistent schema
 | 
						|
          # For those reasons, we make sure that we drop temp_undo_cleanup_column
 | 
						|
          #  if an error is caught
 | 
						|
          if column_exists?(table, temp_undo_cleanup_column)
 | 
						|
            remove_column(table, temp_undo_cleanup_column)
 | 
						|
          end
 | 
						|
 | 
						|
          raise
 | 
						|
        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)
 | 
						|
 | 
						|
        remove_rename_triggers(table, trigger_name)
 | 
						|
 | 
						|
        remove_column(table, old)
 | 
						|
      end
 | 
						|
 | 
						|
      # Reverses the operations performed by cleanup_concurrent_column_rename.
 | 
						|
      #
 | 
						|
      # This method adds back the old_column removed
 | 
						|
      # by cleanup_concurrent_column_rename.
 | 
						|
      # It also adds back the (old_column > new_column) trigger that is removed
 | 
						|
      # by 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 old column. If no type is given the new column's
 | 
						|
      #        type is used.
 | 
						|
      # batch_column_name - option is for tables without primary key, in this
 | 
						|
      #        case another unique integer column can be used. Example: :user_id
 | 
						|
      def undo_cleanup_concurrent_column_rename(table, old, new, type: nil, batch_column_name: :id)
 | 
						|
        unless column_exists?(table, batch_column_name)
 | 
						|
          raise "Column #{batch_column_name} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        if transaction_open?
 | 
						|
          raise 'undo_cleanup_concurrent_column_rename can not be run inside a transaction'
 | 
						|
        end
 | 
						|
 | 
						|
        check_trigger_permissions!(table)
 | 
						|
 | 
						|
        create_column_from(table, new, old, type: type, batch_column_name: batch_column_name)
 | 
						|
 | 
						|
        install_rename_triggers(table, old, new)
 | 
						|
      end
 | 
						|
 | 
						|
      def convert_to_type_column(column, from_type, to_type)
 | 
						|
        "#{column}_convert_#{from_type}_to_#{to_type}"
 | 
						|
      end
 | 
						|
 | 
						|
      def convert_to_bigint_column(column)
 | 
						|
        "#{column}_convert_to_bigint"
 | 
						|
      end
 | 
						|
 | 
						|
      # Initializes the conversion of a set of integer columns to bigint
 | 
						|
      #
 | 
						|
      # It can be used for converting both a Primary Key and any Foreign Keys
 | 
						|
      # that may reference it or any other integer column that we may want to
 | 
						|
      # upgrade (e.g. columns that store IDs, but are not set as FKs).
 | 
						|
      #
 | 
						|
      # - For primary keys and Foreign Keys (or other columns) defined as NOT NULL,
 | 
						|
      #    the new bigint column is added with a hardcoded NOT NULL DEFAULT 0
 | 
						|
      #    which allows us to skip a very costly verification step once we
 | 
						|
      #    are ready to switch it.
 | 
						|
      #   This is crucial for Primary Key conversions, because setting a column
 | 
						|
      #    as the PK converts even check constraints to NOT NULL constraints
 | 
						|
      #    and forces an inline re-verification of the whole table.
 | 
						|
      # - It sets up a trigger to keep the two columns in sync.
 | 
						|
      #
 | 
						|
      #   Note: this helper is intended to be used in a regular (pre-deployment) migration.
 | 
						|
      #
 | 
						|
      #   This helper is part 1 of a multi-step migration process:
 | 
						|
      #   1. initialize_conversion_of_integer_to_bigint to create the new columns and database trigger
 | 
						|
      #   2. backfill_conversion_of_integer_to_bigint to copy historic data using background migrations
 | 
						|
      #   3. remaining steps TBD, see #288005
 | 
						|
      #
 | 
						|
      # table - The name of the database table containing the column
 | 
						|
      # columns - The name, or array of names, of the column(s) that we want to convert to bigint.
 | 
						|
      # primary_key - The name of the primary key column (most often :id)
 | 
						|
      def initialize_conversion_of_integer_to_bigint(table, columns, primary_key: :id)
 | 
						|
        mappings = Array(columns).map do |c|
 | 
						|
          {
 | 
						|
            c => {
 | 
						|
              from_type: :int,
 | 
						|
              to_type: :bigint,
 | 
						|
              default_value: 0
 | 
						|
            }
 | 
						|
          }
 | 
						|
        end.reduce(&:merge)
 | 
						|
 | 
						|
        create_temporary_columns_and_triggers(
 | 
						|
          table,
 | 
						|
          mappings,
 | 
						|
          primary_key: primary_key,
 | 
						|
          old_bigint_column_naming: true
 | 
						|
        )
 | 
						|
      end
 | 
						|
 | 
						|
      # Reverts `initialize_conversion_of_integer_to_bigint`
 | 
						|
      #
 | 
						|
      # table - The name of the database table containing the columns
 | 
						|
      # columns - The name, or array of names, of the column(s) that we're converting to bigint.
 | 
						|
      def revert_initialize_conversion_of_integer_to_bigint(table, columns)
 | 
						|
        columns = Array.wrap(columns)
 | 
						|
        temporary_columns = columns.map { |column| convert_to_bigint_column(column) }
 | 
						|
 | 
						|
        trigger_name = rename_trigger_name(table, columns, temporary_columns)
 | 
						|
        remove_rename_triggers(table, trigger_name)
 | 
						|
 | 
						|
        temporary_columns.each { |column| remove_column(table, column, if_exists: true) }
 | 
						|
      end
 | 
						|
      alias_method :cleanup_conversion_of_integer_to_bigint, :revert_initialize_conversion_of_integer_to_bigint
 | 
						|
 | 
						|
      # Reverts `cleanup_conversion_of_integer_to_bigint`
 | 
						|
      #
 | 
						|
      # table - The name of the database table containing the columns
 | 
						|
      # columns - The name, or array of names, of the column(s) that we have converted to bigint.
 | 
						|
      # primary_key - The name of the primary key column (most often :id)
 | 
						|
      def restore_conversion_of_integer_to_bigint(table, columns, primary_key: :id)
 | 
						|
        mappings = Array(columns).map do |c|
 | 
						|
          {
 | 
						|
            c => {
 | 
						|
              from_type: :bigint,
 | 
						|
              to_type: :int,
 | 
						|
              default_value: 0
 | 
						|
            }
 | 
						|
          }
 | 
						|
        end.reduce(&:merge)
 | 
						|
 | 
						|
        create_temporary_columns_and_triggers(
 | 
						|
          table,
 | 
						|
          mappings,
 | 
						|
          primary_key: primary_key,
 | 
						|
          old_bigint_column_naming: true
 | 
						|
        )
 | 
						|
      end
 | 
						|
 | 
						|
      # Backfills the new columns used in an integer-to-bigint conversion using background migrations.
 | 
						|
      #
 | 
						|
      # - This helper should be called from a post-deployment migration.
 | 
						|
      # - In order for this helper to work properly,  the new columns must be first initialized with
 | 
						|
      #   the `initialize_conversion_of_integer_to_bigint` helper.
 | 
						|
      # - It tracks the scheduled background jobs through Gitlab::Database::BackgroundMigration::BatchedMigration,
 | 
						|
      #   which allows a more thorough check that all jobs succeeded in the
 | 
						|
      #   cleanup migration and is way faster for very large tables.
 | 
						|
      #
 | 
						|
      #   Note: this helper is intended to be used in a post-deployment migration, to ensure any new code is
 | 
						|
      #   deployed (including background job changes) before we begin processing the background migration.
 | 
						|
      #
 | 
						|
      #   This helper is part 2 of a multi-step migration process:
 | 
						|
      #   1. initialize_conversion_of_integer_to_bigint to create the new columns and database trigger
 | 
						|
      #   2. backfill_conversion_of_integer_to_bigint to copy historic data using background migrations
 | 
						|
      #   3. remaining steps TBD, see #288005
 | 
						|
      #
 | 
						|
      # table - The name of the database table containing the column
 | 
						|
      # columns - The name, or an array of names, of the column(s) we want to convert to bigint.
 | 
						|
      # primary_key - The name of the primary key column (most often :id)
 | 
						|
      # batch_size - The number of rows to schedule in a single background migration
 | 
						|
      # sub_batch_size - The smaller batches that will be used by each scheduled job
 | 
						|
      #   to update the table. Useful to keep each update at ~100ms while executing
 | 
						|
      #   more updates per interval (2.minutes)
 | 
						|
      #   Note that each execution of a sub-batch adds a constant 100ms sleep
 | 
						|
      #    time in between the updates, which must be taken into account
 | 
						|
      #    while calculating the batch, sub_batch and interval values.
 | 
						|
      # interval - The time interval between every background migration
 | 
						|
      #
 | 
						|
      # example:
 | 
						|
      # Assume that we have figured out that updating 200 records of the events
 | 
						|
      #  table takes ~100ms on average.
 | 
						|
      # We can set the sub_batch_size to 200, leave the interval to the default
 | 
						|
      #  and set the batch_size to 50_000 which will require
 | 
						|
      #  ~50s = (50000 / 200) * (0.1 + 0.1) to complete and leaves breathing space
 | 
						|
      #  between the scheduled jobs
 | 
						|
      def backfill_conversion_of_integer_to_bigint(
 | 
						|
        table,
 | 
						|
        columns,
 | 
						|
        primary_key: :id,
 | 
						|
        batch_size: 20_000,
 | 
						|
        sub_batch_size: 1000,
 | 
						|
        pause_ms: 100,
 | 
						|
        interval: 2.minutes
 | 
						|
      )
 | 
						|
 | 
						|
        unless table_exists?(table)
 | 
						|
          raise "Table #{table} does not exist"
 | 
						|
        end
 | 
						|
 | 
						|
        unless column_exists?(table, primary_key)
 | 
						|
          raise "Column #{primary_key} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        conversions = Array.wrap(columns).to_h do |column|
 | 
						|
          raise ArgumentError, "Column #{column} does not exist on #{table}" unless column_exists?(table, column)
 | 
						|
 | 
						|
          temporary_name = convert_to_bigint_column(column)
 | 
						|
          raise ArgumentError, "Column #{temporary_name} does not exist on #{table}" unless column_exists?(table, temporary_name)
 | 
						|
 | 
						|
          [column, temporary_name]
 | 
						|
        end
 | 
						|
 | 
						|
        queue_batched_background_migration(
 | 
						|
          'CopyColumnUsingBackgroundMigrationJob',
 | 
						|
          table,
 | 
						|
          primary_key,
 | 
						|
          conversions.keys,
 | 
						|
          conversions.values,
 | 
						|
          job_interval: interval,
 | 
						|
          pause_ms: pause_ms,
 | 
						|
          batch_size: batch_size,
 | 
						|
          sub_batch_size: sub_batch_size)
 | 
						|
      end
 | 
						|
 | 
						|
      # Reverts `backfill_conversion_of_integer_to_bigint`
 | 
						|
      #
 | 
						|
      # table - The name of the database table containing the column
 | 
						|
      # columns - The name, or an array of names, of the column(s) we want to convert to bigint.
 | 
						|
      # primary_key - The name of the primary key column (most often :id)
 | 
						|
      def revert_backfill_conversion_of_integer_to_bigint(table, columns, primary_key: :id)
 | 
						|
        columns = Array.wrap(columns)
 | 
						|
 | 
						|
        conditions = ActiveRecord::Base.sanitize_sql(
 | 
						|
          [
 | 
						|
            'job_class_name = :job_class_name AND table_name = :table_name AND column_name = :column_name AND job_arguments = :job_arguments',
 | 
						|
            job_class_name: 'CopyColumnUsingBackgroundMigrationJob',
 | 
						|
            table_name: table,
 | 
						|
            column_name: primary_key,
 | 
						|
            job_arguments: [columns, columns.map { |column| convert_to_bigint_column(column) }].to_json
 | 
						|
          ])
 | 
						|
 | 
						|
        execute("DELETE FROM batched_background_migrations WHERE #{conditions}")
 | 
						|
      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)
 | 
						|
 | 
						|
          if name.length > 63
 | 
						|
            digest = Digest::SHA256.hexdigest(name).first(10)
 | 
						|
            name = "idx_copy_#{digest}"
 | 
						|
          end
 | 
						|
 | 
						|
          options = {
 | 
						|
            unique: index.unique,
 | 
						|
            name: name,
 | 
						|
            length: index.lengths,
 | 
						|
            order: index.orders
 | 
						|
          }
 | 
						|
 | 
						|
          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[:opclass] = 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
 | 
						|
 | 
						|
        column = columns(table).find { |column| column.name == name }
 | 
						|
        raise(missing_schema_object_message(table, "column", name)) if column.nil?
 | 
						|
 | 
						|
        column
 | 
						|
      end
 | 
						|
 | 
						|
      # This will replace the first occurrence of a string in a column with
 | 
						|
      # the replacement using `regexp_replace`
 | 
						|
      def replace_sql(column, pattern, replacement)
 | 
						|
        quoted_pattern = Arel::Nodes::Quoted.new(pattern.to_s)
 | 
						|
        quoted_replacement = Arel::Nodes::Quoted.new(replacement.to_s)
 | 
						|
 | 
						|
        replace = Arel::Nodes::NamedFunction.new(
 | 
						|
          "regexp_replace", [column, quoted_pattern, quoted_replacement]
 | 
						|
        )
 | 
						|
 | 
						|
        Arel::Nodes::SqlLiteral.new(replace.to_sql)
 | 
						|
      end
 | 
						|
 | 
						|
      def remove_foreign_key_if_exists(source, target = nil, **kwargs)
 | 
						|
        reverse_lock_order = kwargs.delete(:reverse_lock_order)
 | 
						|
        return unless foreign_key_exists?(source, target, **kwargs)
 | 
						|
 | 
						|
        if target && reverse_lock_order && transaction_open?
 | 
						|
          execute("LOCK TABLE #{target}, #{source} IN ACCESS EXCLUSIVE MODE")
 | 
						|
        end
 | 
						|
 | 
						|
        if target
 | 
						|
          remove_foreign_key(source, target, **kwargs)
 | 
						|
        else
 | 
						|
          remove_foreign_key(source, **kwargs)
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      def remove_foreign_key_without_error(*args, **kwargs)
 | 
						|
        remove_foreign_key(*args, **kwargs)
 | 
						|
      rescue ArgumentError
 | 
						|
      end
 | 
						|
 | 
						|
      def check_trigger_permissions!(table)
 | 
						|
        unless Grant.create_and_execute_trigger?(table)
 | 
						|
          dbname = ApplicationRecord.database.database_name
 | 
						|
          user = ApplicationRecord.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
 | 
						|
 | 
						|
This 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
 | 
						|
 | 
						|
      # Fetches indexes on a column by name for postgres.
 | 
						|
      #
 | 
						|
      # This will include indexes using an expression on the column, for example:
 | 
						|
      # `CREATE INDEX CONCURRENTLY index_name ON table (LOWER(column));`
 | 
						|
      #
 | 
						|
      # We can remove this when upgrading to Rails 5 with an updated `index_exists?`:
 | 
						|
      # - https://github.com/rails/rails/commit/edc2b7718725016e988089b5fb6d6fb9d6e16882
 | 
						|
      #
 | 
						|
      # Or this can be removed when we no longer support postgres < 9.5, so we
 | 
						|
      # can use `CREATE INDEX IF NOT EXISTS`.
 | 
						|
      def index_exists_by_name?(table, index)
 | 
						|
        # We can't fall back to the normal `index_exists?` method because that
 | 
						|
        # does not find indexes without passing a column name.
 | 
						|
        if indexes(table).map(&:name).include?(index.to_s)
 | 
						|
          true
 | 
						|
        else
 | 
						|
          postgres_exists_by_name?(table, index)
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      def postgres_exists_by_name?(table, name)
 | 
						|
        index_sql = <<~SQL
 | 
						|
          SELECT COUNT(*)
 | 
						|
          FROM pg_catalog.pg_indexes
 | 
						|
          WHERE schemaname = #{connection.quote(current_schema)}
 | 
						|
            AND tablename = #{connection.quote(table)}
 | 
						|
            AND indexname = #{connection.quote(name)}
 | 
						|
        SQL
 | 
						|
 | 
						|
        connection.select_value(index_sql).to_i > 0
 | 
						|
      end
 | 
						|
 | 
						|
      def create_or_update_plan_limit(limit_name, plan_name, limit_value)
 | 
						|
        limit_name_quoted = quote_column_name(limit_name)
 | 
						|
        plan_name_quoted = quote(plan_name)
 | 
						|
        limit_value_quoted = quote(limit_value)
 | 
						|
 | 
						|
        execute <<~SQL
 | 
						|
          INSERT INTO plan_limits (plan_id, #{limit_name_quoted})
 | 
						|
          SELECT id, #{limit_value_quoted} FROM plans WHERE name = #{plan_name_quoted} LIMIT 1
 | 
						|
          ON CONFLICT (plan_id) DO UPDATE SET #{limit_name_quoted} = EXCLUDED.#{limit_name_quoted};
 | 
						|
        SQL
 | 
						|
      end
 | 
						|
 | 
						|
      # Note this should only be used with very small tables
 | 
						|
      def backfill_iids(table)
 | 
						|
        sql = <<-END
 | 
						|
          UPDATE #{table}
 | 
						|
          SET iid = #{table}_with_calculated_iid.iid_num
 | 
						|
          FROM (
 | 
						|
            SELECT id, ROW_NUMBER() OVER (PARTITION BY project_id ORDER BY id ASC) AS iid_num FROM #{table}
 | 
						|
          ) AS #{table}_with_calculated_iid
 | 
						|
          WHERE #{table}.id = #{table}_with_calculated_iid.id
 | 
						|
        END
 | 
						|
 | 
						|
        execute(sql)
 | 
						|
      end
 | 
						|
 | 
						|
      def add_primary_key_using_index(table_name, pk_name, index_to_use)
 | 
						|
        execute <<~SQL
 | 
						|
          ALTER TABLE #{quote_table_name(table_name)} ADD CONSTRAINT #{quote_table_name(pk_name)} PRIMARY KEY USING INDEX #{quote_table_name(index_to_use)}
 | 
						|
        SQL
 | 
						|
      end
 | 
						|
 | 
						|
      def swap_primary_key(table_name, primary_key_name, index_to_use)
 | 
						|
        with_lock_retries(raise_on_exhaustion: true) do
 | 
						|
          drop_constraint(table_name, primary_key_name, cascade: true)
 | 
						|
          add_primary_key_using_index(table_name, primary_key_name, index_to_use)
 | 
						|
        end
 | 
						|
      end
 | 
						|
      alias_method :unswap_primary_key, :swap_primary_key
 | 
						|
 | 
						|
      def drop_sequence(table_name, column_name, sequence_name)
 | 
						|
        execute <<~SQL
 | 
						|
          ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} DROP DEFAULT;
 | 
						|
          DROP SEQUENCE IF EXISTS #{quote_table_name(sequence_name)}
 | 
						|
        SQL
 | 
						|
      end
 | 
						|
 | 
						|
      def add_sequence(table_name, column_name, sequence_name, start_value)
 | 
						|
        execute <<~SQL
 | 
						|
          CREATE SEQUENCE #{quote_table_name(sequence_name)} START #{start_value};
 | 
						|
          ALTER TABLE #{quote_table_name(table_name)} ALTER COLUMN #{quote_column_name(column_name)} SET DEFAULT nextval(#{quote(sequence_name)})
 | 
						|
        SQL
 | 
						|
      end
 | 
						|
 | 
						|
      # rubocop:disable Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
 | 
						|
      def create_temporary_columns_and_triggers(table, mappings, primary_key: :id, old_bigint_column_naming: false)
 | 
						|
        raise ArgumentError, "No mappings for column conversion provided" if mappings.blank?
 | 
						|
 | 
						|
        unless mappings.values.all? { |values| mapping_has_required_columns?(values) }
 | 
						|
          raise ArgumentError, "Some mappings don't have required keys provided"
 | 
						|
        end
 | 
						|
 | 
						|
        neutral_values_for_type = {
 | 
						|
          int: 0,
 | 
						|
          bigint: 0,
 | 
						|
          uuid: '00000000-0000-0000-0000-000000000000'
 | 
						|
        }
 | 
						|
 | 
						|
        unless table_exists?(table)
 | 
						|
          raise "Table #{table} does not exist"
 | 
						|
        end
 | 
						|
 | 
						|
        unless column_exists?(table, primary_key)
 | 
						|
          raise "Column #{primary_key} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        columns = mappings.keys
 | 
						|
        columns.each do |column|
 | 
						|
          next if column_exists?(table, column)
 | 
						|
 | 
						|
          raise ArgumentError, "Column #{column} does not exist on #{table}"
 | 
						|
        end
 | 
						|
 | 
						|
        check_trigger_permissions!(table)
 | 
						|
 | 
						|
        if old_bigint_column_naming
 | 
						|
          mappings.each do |column, params|
 | 
						|
            params.merge!(
 | 
						|
              temporary_column_name: convert_to_bigint_column(column)
 | 
						|
            )
 | 
						|
          end
 | 
						|
        else
 | 
						|
          mappings.each do |column, params|
 | 
						|
            params.merge!(
 | 
						|
              temporary_column_name: convert_to_type_column(column, params[:from_type], params[:to_type])
 | 
						|
            )
 | 
						|
          end
 | 
						|
        end
 | 
						|
 | 
						|
        with_lock_retries do
 | 
						|
          mappings.each do |(column_name, params)|
 | 
						|
            column = column_for(table, column_name)
 | 
						|
            temporary_name = params[:temporary_column_name]
 | 
						|
            data_type = params[:to_type]
 | 
						|
            default_value = params[:default_value]
 | 
						|
 | 
						|
            if (column.name.to_s == primary_key.to_s) || !column.null
 | 
						|
              # If the column to be converted is either a PK or is defined as NOT NULL,
 | 
						|
              # set it to `NOT NULL DEFAULT 0` and we'll copy paste the correct values bellow
 | 
						|
              # That way, we skip the expensive validation step required to add
 | 
						|
              #  a NOT NULL constraint at the end of the process
 | 
						|
              add_column(
 | 
						|
                table,
 | 
						|
                temporary_name,
 | 
						|
                data_type,
 | 
						|
                default: column.default || default_value || neutral_values_for_type.fetch(data_type),
 | 
						|
                null: false
 | 
						|
              )
 | 
						|
            else
 | 
						|
              add_column(
 | 
						|
                table,
 | 
						|
                temporary_name,
 | 
						|
                data_type,
 | 
						|
                default: column.default
 | 
						|
              )
 | 
						|
            end
 | 
						|
          end
 | 
						|
 | 
						|
          old_column_names = mappings.keys
 | 
						|
          temporary_column_names = mappings.values.map { |v| v[:temporary_column_name] }
 | 
						|
          install_rename_triggers(table, old_column_names, temporary_column_names)
 | 
						|
        end
 | 
						|
      end
 | 
						|
      # rubocop:enable Metrics/CyclomaticComplexity,Metrics/PerceivedComplexity
 | 
						|
 | 
						|
      def partition?(table_name)
 | 
						|
        if view_exists?(:postgres_partitions)
 | 
						|
          Gitlab::Database::PostgresPartition.partition_exists?(table_name)
 | 
						|
        else
 | 
						|
          Gitlab::Database::PostgresPartition.legacy_partition_exists?(table_name)
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      def table_partitioned?(table_name)
 | 
						|
        Gitlab::Database::PostgresPartitionedTable
 | 
						|
          .find_by_name_in_current_schema(table_name)
 | 
						|
          .present?
 | 
						|
      end
 | 
						|
 | 
						|
      # While it is safe to call `change_column_default` on a column without
 | 
						|
      # default it would still require access exclusive lock on the table
 | 
						|
      # and for tables with high autovacuum(wraparound prevention) it will
 | 
						|
      # fail if their executions overlap.
 | 
						|
      #
 | 
						|
      def remove_column_default(table_name, column_name)
 | 
						|
        column = connection.columns(table_name).find { |col| col.name == column_name.to_s }
 | 
						|
 | 
						|
        if column.default || column.default_function
 | 
						|
          change_column_default(table_name, column_name, to: nil)
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      def lock_tables(*tables, mode: :access_exclusive)
 | 
						|
        execute("LOCK TABLE #{tables.join(', ')} IN #{mode.to_s.upcase.tr('_', ' ')} MODE")
 | 
						|
      end
 | 
						|
 | 
						|
      private
 | 
						|
 | 
						|
      def multiple_columns(columns, separator: ', ')
 | 
						|
        Array.wrap(columns).join(separator)
 | 
						|
      end
 | 
						|
 | 
						|
      def cascade_statement(cascade)
 | 
						|
        cascade ? 'CASCADE' : ''
 | 
						|
      end
 | 
						|
 | 
						|
      def validate_check_constraint_name!(constraint_name)
 | 
						|
        if constraint_name.to_s.length > MAX_IDENTIFIER_NAME_LENGTH
 | 
						|
          raise "The maximum allowed constraint name is #{MAX_IDENTIFIER_NAME_LENGTH} characters"
 | 
						|
        end
 | 
						|
      end
 | 
						|
 | 
						|
      # mappings => {} where keys are column names and values are hashes with the following keys:
 | 
						|
      # from_type - from which type we're migrating
 | 
						|
      # to_type - to which type we're migrating
 | 
						|
      # default_value - custom default value, if not provided will be taken from neutral_values_for_type
 | 
						|
      def mapping_has_required_columns?(mapping)
 | 
						|
        %i[from_type to_type].map do |required_key|
 | 
						|
          mapping.has_key?(required_key)
 | 
						|
        end.all?
 | 
						|
      end
 | 
						|
 | 
						|
      def column_is_nullable?(table, column)
 | 
						|
        # Check if table.column has not been defined with NOT NULL
 | 
						|
        check_sql = <<~SQL
 | 
						|
          SELECT c.is_nullable
 | 
						|
          FROM information_schema.columns c
 | 
						|
          WHERE c.table_schema = #{connection.quote(current_schema)}
 | 
						|
            AND c.table_name = #{connection.quote(table)}
 | 
						|
            AND c.column_name = #{connection.quote(column)}
 | 
						|
        SQL
 | 
						|
 | 
						|
        connection.select_value(check_sql) == 'YES'
 | 
						|
      end
 | 
						|
 | 
						|
      def missing_schema_object_message(table, type, name)
 | 
						|
        <<~MESSAGE
 | 
						|
          Could not find #{type} "#{name}" on table "#{table}" which was referenced during the migration.
 | 
						|
          This issue could be caused by the database schema straying from the expected state.
 | 
						|
 | 
						|
          To resolve this issue, please verify:
 | 
						|
            1. all previous migrations have completed
 | 
						|
            2. the database objects used in this migration match the Rails definition in schema.rb or structure.sql
 | 
						|
 | 
						|
        MESSAGE
 | 
						|
      end
 | 
						|
 | 
						|
      def tables_match?(target_table, foreign_key_table)
 | 
						|
        target_table.blank? || foreign_key_table == target_table
 | 
						|
      end
 | 
						|
 | 
						|
      def options_match?(foreign_key_options, options)
 | 
						|
        options.all? { |k, v| foreign_key_options[k].to_s == v.to_s }
 | 
						|
      end
 | 
						|
 | 
						|
      def on_delete_statement(on_delete)
 | 
						|
        return '' if on_delete.blank?
 | 
						|
        return 'ON DELETE SET NULL' if on_delete == :nullify
 | 
						|
 | 
						|
        "ON DELETE #{on_delete.upcase}"
 | 
						|
      end
 | 
						|
 | 
						|
      def on_update_statement(on_update)
 | 
						|
        return '' if on_update.blank?
 | 
						|
        return 'ON UPDATE SET NULL' if on_update == :nullify
 | 
						|
 | 
						|
        "ON UPDATE #{on_update.upcase}"
 | 
						|
      end
 | 
						|
 | 
						|
      def create_column_from(table, old, new, type: nil, batch_column_name: :id, type_cast_function: nil, limit: nil)
 | 
						|
        old_col = column_for(table, old)
 | 
						|
        new_type = type || old_col.type
 | 
						|
        new_limit = limit || old_col.limit
 | 
						|
 | 
						|
        add_column(table, new, new_type,
 | 
						|
                   limit: new_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) unless old_col.default.nil?
 | 
						|
 | 
						|
        old_value = Arel::Table.new(table)[old]
 | 
						|
 | 
						|
        if type_cast_function.present?
 | 
						|
          old_value = Arel::Nodes::NamedFunction.new(type_cast_function, [old_value])
 | 
						|
        end
 | 
						|
 | 
						|
        Gitlab::Database::QueryAnalyzers::RestrictAllowedSchemas.with_suppressed do
 | 
						|
          Gitlab::Database::QueryAnalyzers::GitlabSchemasValidateConnection.with_suppressed do
 | 
						|
            update_column_in_batches(table, new, old_value, batch_column_name: batch_column_name, disable_lock_writes: true)
 | 
						|
          end
 | 
						|
        end
 | 
						|
 | 
						|
        add_not_null_constraint(table, new) unless old_col.null
 | 
						|
 | 
						|
        copy_indexes(table, old, new)
 | 
						|
        copy_foreign_keys(table, old, new)
 | 
						|
        copy_check_constraints(table, old, new)
 | 
						|
      end
 | 
						|
 | 
						|
      def validate_timestamp_column_name!(column_name)
 | 
						|
        return if column_name.to_s.end_with?('_at')
 | 
						|
 | 
						|
        raise <<~MESSAGE
 | 
						|
          Illegal timestamp column name! Got #{column_name}.
 | 
						|
          Must end with `_at`}
 | 
						|
        MESSAGE
 | 
						|
      end
 | 
						|
 | 
						|
      def execute_add_concurrent_foreign_key(source, target, options)
 | 
						|
        # 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.
 | 
						|
        not_valid = 'NOT VALID'
 | 
						|
        lock_mode = 'SHARE ROW EXCLUSIVE'
 | 
						|
 | 
						|
        if table_partitioned?(source)
 | 
						|
          not_valid = ''
 | 
						|
          lock_mode = 'ACCESS EXCLUSIVE'
 | 
						|
        end
 | 
						|
 | 
						|
        with_lock_retries do
 | 
						|
          execute("LOCK TABLE #{target}, #{source} IN #{lock_mode} MODE") if options[:reverse_lock_order]
 | 
						|
          execute(<<~SQL.squish)
 | 
						|
            ALTER TABLE #{source}
 | 
						|
            ADD CONSTRAINT #{options[:name]}
 | 
						|
            FOREIGN KEY (#{multiple_columns(options[:column])})
 | 
						|
            REFERENCES #{target} (#{multiple_columns(options[:target_column])})
 | 
						|
            #{on_update_statement(options[:on_update])}
 | 
						|
            #{on_delete_statement(options[:on_delete])}
 | 
						|
            #{not_valid};
 | 
						|
          SQL
 | 
						|
        end
 | 
						|
      end
 | 
						|
    end
 | 
						|
  end
 | 
						|
end
 |