disabie view-protocol for certain places:
1. While a transaction is in progress: a view gets locked for a
transaction duration, so DROP VIEW from a servicing conneciton
deadlocks. We can't just disable servicing connection, as
CREATE VIEW and DROP VIEW commit implicitly.
2. For querying Opened_table_definitions: the actual query executed
is `SELECT * FROM mysqltest_tmp_v`, then the view is dropped