use update(model).select().values to update, instead of manually commit

as the title said.

@dosu what is your opinion.

I want improve the orm speed.

but use orm style may able to trigger the ORM-level events.

The issue names no files, tests, or entry points. First compare the current manual commit path with update(model).select().values, then establish whether ORM-level events must still fire; done requires an agreed implementation scope plus evidence of improved ORM speed without breaking those events.

Written by the indexing model from the issue text.