In theory the proper place to do that would be a pragma such as, lets say, `pragma transaction_default=deferred|immediate|exclusive` with the default behaviour being deferred, which would set the "default behaviour" for beginning a transaction (whether by begin or savepoint when no explicit transaction type is given). This would not help, however, in those cases where a "wrapper" implements a transaction by spinning up a new connection for the transaction since there would be no way without modifying the wrapper to alter the default behaviour. And if you have to modify the wrapper anyway, then why not just modify the wrapper to work more better in the first place by allowing the specification of whether to start a specific type of transaction?