class ActiveRecord::ConnectionAdapters::RedshiftAdapter
The PostgreSQL adapter works with the native C (bitbucket.org/ged/ruby-pg) driver.
Options:
-
:host
- Defaults to a Unix-domain socket in /tmp. On machines without Unix-domain sockets, the default is to connect to localhost. -
:port
- Defaults to 5432. -
:username
- Defaults to be the same as the operating system name of the user running the application. -
:password
- Password to be used if the server demands password authentication. -
:database
- Defaults to be the same as the user name. -
:schema_search_path
- An optional schema search path for the connection given as a string of comma-separated schema names. This is backward-compatible with the:schema_order
option. -
:encoding
- An optional client encoding that is used in aSET client_encoding TO <encoding>
call on the connection. -
:min_messages
- An optional client min messages that is used in aSET client_min_messages TO <min_messages>
call on the connection. -
:variables
- An optional hash of additional parameters that will be used inSET SESSION key = val
calls on the connection. -
:insert_returning
- Does nothing forRedshift
.
Any further options are used as connection parameters to libpq. See www.postgresql.org/docs/9.1/static/libpq-connect.html for the list of parameters.
In addition, default connection parameters of libpq can be set per environment variables. See www.postgresql.org/docs/9.1/static/libpq-envars.html .
Constants
- ADAPTER_NAME
- NATIVE_DATABASE_TYPES
Public Class Methods
Initializes and connects a PostgreSQL adapter.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 195 def initialize(connection, logger, connection_parameters, config) super(connection, logger) @visitor = Arel::Visitors::PostgreSQL.new self @prepared_statements = false @connection_parameters, @config = connection_parameters, config # @local_tz is initialized as nil to avoid warnings when connect tries to use it @local_tz = nil @table_alias_length = nil connect @statements = StatementPool.new @connection, self.class.type_cast_config_to_integer(config.fetch(:statement_limit) { 1000 }) @type_map = Type::HashLookupTypeMap.new initialize_type_map(type_map) @local_tz = execute('SHOW TIME ZONE', 'SCHEMA').first["TimeZone"] @use_insert_returning = @config.key?(:insert_returning) ? self.class.type_cast_config_to_boolean(@config[:insert_returning]) : false end
Public Instance Methods
Is this connection alive and ready for queries?
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 227 def active? @connection.query 'SELECT 1' true rescue PGError false end
Clears the prepared statements cache.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 218 def clear_cache! @statements.clear end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 307 def disable_extension(name) end
Disconnects from the database if already connected. Otherwise, this method does nothing.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 253 def disconnect! super @connection.close rescue nil end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 304 def enable_extension(name) end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 310 def extension_enabled?(name) false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 137 def index_algorithms { concurrently: 'CONCURRENTLY' } end
Close then reopen the connection.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 235 def reconnect! super @connection.reset configure_connection end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 241 def reset! clear_cache! reset_transaction unless @connection.transaction_status == ::PG::PQTRANS_IDLE @connection.query 'ROLLBACK' end @connection.query 'DISCARD ALL' configure_connection end
Set the authorized user for this session
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 320 def session_auth=(user) clear_cache! exec_query "SET SESSION AUTHORIZATION #{user}" end
Enable standard-conforming strings if available.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 273 def set_standard_conforming_strings old, self.client_min_messages = client_min_messages, 'panic' execute('SET standard_conforming_strings = on', 'SCHEMA') rescue nil ensure self.client_min_messages = old end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 280 def supports_ddl_transactions? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 284 def supports_explain? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 288 def supports_extensions? false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 129 def supports_foreign_keys? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 300 def supports_import? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 117 def supports_index_sort_order? false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 296 def supports_materialized_views? false end
Returns true, since this connection adapter supports migrations.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 263 def supports_migrations? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 121 def supports_partial_index? false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 292 def supports_ranges? false end
Returns true
, since this connection adapter supports prepared statement caching.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 113 def supports_statement_cache? true end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 125 def supports_transaction_isolation? false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 133 def supports_views? true end
Returns the configured supported identifier length supported by PostgreSQL
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 315 def table_alias_length @table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 222 def truncate(table_name, name = nil) exec_query "TRUNCATE TABLE #{quote_table_name(table_name)}", name, [] end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 325 def use_insert_returning? false end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 329 def valid_type?(type) !native_database_types[type].nil? end
Protected Instance Methods
Returns the version of the connected PostgreSQL server.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 355 def redshift_version @connection.server_version end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 359 def translate_exception(exception, message) return exception unless exception.respond_to?(:result) case exception.message when /duplicate key value violates unique constraint/ RecordNotUnique.new(message, exception) when /violates foreign key constraint/ InvalidForeignKey.new(message, exception) else super end end
Private Instance Methods
Configures the encoding, verbosity, schema search path, and time zone of the connection. This is called by connect
and should not be called manually.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 581 def configure_connection if @config[:encoding] @connection.set_client_encoding(@config[:encoding]) end self.schema_search_path = @config[:schema_search_path] || @config[:schema_order] # SET statements from :variables config hash # http://www.postgresql.org/docs/8.3/static/sql-set.html variables = @config[:variables] || {} variables.map do |k, v| if v == ':default' || v == :default # Sets the value to the global or compile default execute("SET SESSION #{k} TO DEFAULT", 'SCHEMA') elsif !v.nil? execute("SET SESSION #{k} TO #{quote(v)}", 'SCHEMA') end end end
Connects to a PostgreSQL server and sets up the adapter depending on the connected server's characteristics.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 567 def connect @connection = PGconn.connect(@connection_parameters) configure_connection rescue ::PG::Error => error if error.message.include?("does not exist") raise ActiveRecord::NoDatabaseError.new(error.message, error) else raise end end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 512 def exec_cache(sql, name, binds) stmt_key = prepare_statement(sql) type_casted_binds = binds.map { |col, val| [col, type_cast(val, col)] } log(sql, name, type_casted_binds, stmt_key) do @connection.exec_prepared(stmt_key, type_casted_binds.map { |_, val| val }) end rescue ActiveRecord::StatementInvalid => e pgerror = e.original_exception # Get the PG code for the failure. Annoyingly, the code for # prepared statements whose return value may have changed is # FEATURE_NOT_SUPPORTED. Check here for more details: # http://git.postgresql.org/gitweb/?p=postgresql.git;a=blob;f=src/backend/utils/cache/plancache.c#l573 begin code = pgerror.result.result_error_field(PGresult::PG_DIAG_SQLSTATE) rescue raise e end if FEATURE_NOT_SUPPORTED == code @statements.delete sql_key(sql) retry else raise e end end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 508 def exec_no_cache(sql, name, binds) log(sql, name, binds) { @connection.async_exec(sql, []) } end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 500 def execute_and_clear(sql, name, binds) result = without_prepared_statement?(binds) ? exec_no_cache(sql, name, binds) : exec_cache(sql, name, binds) ret = yield result result.clear ret end
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 605 def last_insert_id_value(sequence_name) last_insert_id_result(sequence_name).rows.first.first end
Prepare the statement if it hasn't been prepared, return the statement key.
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 549 def prepare_statement(sql) sql_key = sql_key(sql) unless @statements.key? sql_key nextkey = @statements.next_key begin @connection.prepare nextkey, sql rescue => e raise translate_exception_class(e, sql) end # Clear the queue @connection.get_last_result @statements[sql_key] = nextkey end @statements[sql_key] end
Returns the statement identifier for the client side cache of statements
# File lib/active_record/connection_adapters/redshift_adapter.rb, line 543 def sql_key(sql) "#{schema_search_path}-#{sql}" end