In CA the state and federal constitutions require that you have a speedy trial if you want one. Specifically that means you are entitled to a trial within 60 days of your 2nd arraignment which follows the prelim. If everyone insisted on their speedy trial rights 95% of cases would get dismissed.
Should I Ever Waive My Right to a Speedy Trial?
In some circumstances it is better to do so. The more serious the charge the more time your attorney needs to prepare. If you force him to go to trial in 60 days he might not be ready. The speedy trial right can be waived until he is ready and then reasserted. If you are facing a murder or rape charge you are better off to let your attorney decide the timing of the trial.
What Happens If I Demand a Speedy Trial and the DA Wants a Continuance Beyond Day 60?
The DA will not even ask for this because he knows that constitutionally he must try you in the 60 day frame. No excuse is good enough to pass the 60th day. Should that day come and go your attorney should be able to get you an immediate dismissal.