Oakland has rent control, with rates of %1.5-%3/yr. If it's a condo, house or 4-plex or under, normal rent control does not apply. Even then, the max is %10/yr, with a max of %30/5yrs.

So if you have a $800/month tenant, it will take over 15 years to get their rent up to the current market rate of ~$2200/yr.