Add new error class `StatementTimeout` which will be raised when statement timeout exceeded (#31129)

We are sometimes using The MAX_EXECUTION_TIME hint for MySQL depending
on the situation. It will prevent catastrophic performance down by wrong
performing queries.

The new error class `StatementTimeout` will make to be easier to handle
that case.

https://dev.mysql.com/doc/refman/5.7/en/optimizer-hints.html#optimizer-hints-execution-time

1 files changed, 5 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/errors.rb b/activerecord/lib/active_record/errors.rb
index 9ef3316393..f77cd23e22 100644
--- a/activerecord/lib/active_record/errors.rb
+++ b/activerecord/lib/active_record/errors.rb
@@ -335,8 +335,11 @@ module ActiveRecord
   class IrreversibleOrderError < ActiveRecordError
   end
 
-  # TransactionTimeout will be raised when lock wait timeout expires.
-  # Wait time value is set by innodb_lock_wait_timeout.
+  # TransactionTimeout will be raised when lock wait timeout exceeded.
   class TransactionTimeout < StatementInvalid
   end
+
+  # StatementTimeout will be raised when statement timeout exceeded.
+  class StatementTimeout < StatementInvalid
+  end
 end