What is the test for determining whether a party is necessary and/or indispensable?

"'Whether a party is necessary and/or indispensable is a matter of trial court discretion in which the court weighs "factors of practical realities and other considerations."' [Citation.]" (City of San Diego, supra, 186 Cal.App.4th at p. 84, quoting County of Imperial v. Superior Court (2007) 152 Cal.App.4th 13, 26.)

Even if a party is indispensable and is not joined, the court has the power to proceed with a case. (City of San Diego, supra, 186 Cal.App.4th at p. 84.) Absence of an indispensable party does not go to a trial court's jurisdiction. The absence may impair the court's ability to grant effective relief, but is not a defect of fundamental, subject matter jurisdiction. (Kraus v. Willow Park Public Golf Course (1977) 73 Cal.App.3d 354, 364-365.)