A California judge has 90 days to issue a decision once it is taken under submission. Failure to make decisions within 90 days may mean that the judge does not receive his or her salary. See Government Code Section 68210.
With the Court budget cuts and resulting lack of staffing, the time to get a ruling for matters taken under submission has been increasing. Judges have 90 days to submit a ruling. After a reasonable amount of time has passed - say two weeks - you may want to call the clerk of the court and politely ask if there is a ruling and if not ask when you think the judge will rule. Most likely you will get a nonresponsive answer, but hopefully the clerk will pass the message along to the judge. If unsuccessful, call the clerk in another 2 weeks. Again, be very pleasant as everyone in the courts are overworked these days and by being difficult, you will gain nothing. If all else fails and after 90 days, you may want to write a letter to the presiding judge with a copy to your judge. Be careful here, as no one likes to be reprimanded, especially a sitting judge.
Article IV section 19 of the California Constitution requires a Judge who has taken a ruling under submission to make a ruling in 90 days. The law says that a Judge may not receive a salary while that ruling remains under submission. In fact, signing a affidavit attesting to such is required in California, and Judges have been disciplined for signing such an affidavit while matters remain under submission. As the saying goes "justice delayed is justice denied". You can report such a judge to the Commission on Judicial Performance, but be advised that it is unlikely to result in anything worthwhile.
California Judges usually resort to the technique of "reserving" the issue so that they do not have to rule upon it. This gets them out of the 90-day rule, and one might suspect the reason for doing is the hope of the court that the case will "dry up and blow away" and thus clear their already overflowing docket. You will see this commonly in family law, for example. An unrepresented litigant will not know what to do in this instance, and will be forced to let the matter drop. However, one practice is to file a motion placing the matter back on calendar asking for a ruling.
You have the right to have your matter heard in a timely manner and frankly, my sympathies go out to you and all other litigants who find their rights cut off in this manner. That is easy for me to say, since I am not the Judge facing the giant stack of files each day, but I do not think the answer is hoping the people who depend upon you for justice simply stop coming to court asking for help.