Lawyer advice request.

Does anybody know about Texas felony records? Suppose a person has a felony charge on his record, but was not convicted, but rather, the case was deferred adjudicated.
How much time has to pass before that can be expunged or sealed? I'm under the impression that it cannot be expunged, but can be sealed after 7 years. I don't know if that's true or not. Would the time period start only after the case was closed?

Thanks.