class ActiveRecord::ConnectionAdapters::PostgreSQLAdapter

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 226
def initialize(connection, logger, connection_parameters, config)
  super(connection, logger)

  @visitor = Arel::Visitors::PostgreSQL.new self
  if self.class.type_cast_config_to_boolean(config.fetch(:prepared_statements) { true })
    @prepared_statements = true
  else
    @prepared_statements = false
  end

  @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 })

  if postgresql_version < 80200
    raise "Your version of PostgreSQL (#{postgresql_version}) is too old, please upgrade!"
  end

  @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]) : true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 266
def active?
  @connection.query 'SELECT 1'
  true
rescue PGError
  false
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 257
def clear_cache!
  @statements.clear
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 343
def disable_extension(name)
  exec_query("DROP EXTENSION IF EXISTS \"#{name}\" CASCADE").tap {
    reload_type_map
  }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 292
def disconnect!
  super
  @connection.close rescue nil
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 337
def enable_extension(name)
  exec_query("CREATE EXTENSION IF NOT EXISTS \"#{name}\"").tap {
    reload_type_map
  }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 349
def extension_enabled?(name)
  if supports_extensions?
    res = exec_query "SELECT EXISTS(SELECT * FROM pg_available_extensions WHERE name = '#{name}' AND installed_version IS NOT NULL) as enabled",
      'SCHEMA'
    res.cast_values.first
  end
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 357
def extensions
  if supports_extensions?
    exec_query("SELECT extname from pg_extension", "SCHEMA").cast_values
  else
    super
  end
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 168
def index_algorithms
  { concurrently: 'CONCURRENTLY' }
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 138
def migration_keys
  super + [:array]
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 274
def reconnect!
  super
  @connection.reset
  configure_connection
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 280
def reset!
  clear_cache!
  reset_transaction
  unless @connection.transaction_status == ::PG::PQTRANS_IDLE
    @connection.query 'ROLLBACK'
  end
  @connection.query 'DISCARD ALL'
  configure_connection
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 371
def session_auth=(user)
  clear_cache!
  exec_query "SET SESSION AUTHORIZATION #{user}"
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 311
def set_standard_conforming_strings
  execute('SET standard_conforming_strings = on', 'SCHEMA')
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 315
def supports_ddl_transactions?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 319
def supports_explain?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 324
def supports_extensions?
  postgresql_version >= 90100
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 160
def supports_foreign_keys?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 148
def supports_index_sort_order?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 333
def supports_materialized_views?
  postgresql_version >= 90300
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 302
def supports_migrations?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 152
def supports_partial_index?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 329
def supports_ranges?
  postgresql_version >= 90200
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 144
def supports_statement_cache?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 156
def supports_transaction_isolation?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 164
def supports_views?
  true
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 366
def table_alias_length
  @table_alias_length ||= query('SHOW max_identifier_length', 'SCHEMA')[0][0].to_i
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 261
def truncate(table_name, name = nil)
  exec_query "TRUNCATE TABLE #{quote_table_name(table_name)}", name, []
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 376
def use_insert_returning?
  @use_insert_returning
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 380
def valid_type?(type)
  !native_database_types[type].nil?
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 406
def postgresql_version
  @connection.server_version
end

# File activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb, line 414
def translate_exception(exception, message)
  return exception unless exception.respond_to?(:result)

  case exception.result.try(:error_field, PGresult::PG_DIAG_SQLSTATE)
  when UNIQUE_VIOLATION
    RecordNotUnique.new(message, exception)
  when FOREIGN_KEY_VIOLATION
    InvalidForeignKey.new(message, exception)
  else
    super
  end
end