* +config.active_record.auto_explain_threshold_in_seconds+ configures the threshold for automatic EXPLAINs (+nil+ disables this feature). Queries exceeding the threshold get their query plan logged. Default is 0.5 in development mode.
+* +config.active_record.dependent_restrict_raises+ will control the behavior when an object with a <tt>:dependent => :restrict</tt> association is deleted. Setting this to false will prevent +DeleteRestrictionError+ from being raised and instead will add an error on the model object. Defaults to false in the development mode.
The MySQL adapter adds one additional configuration option:
* +ActiveRecord::ConnectionAdapters::MysqlAdapter.emulate_booleans+ controls whether Active Record will consider all +tinyint(1)+ columns in a MySQL database to be booleans and is true by default.