8. A non-transitory computer-readable storage device having instructions stored thereon, execution of which by a computing device, cause said computing device to perform operations comprising: determining, by at least one processor, a presence of a disjunction expression in a complex query expression, the disjunction expression including a disjunctive operator and a plurality of disjunctive conditions, wherein the complex query expression comprises a conjunction expression including a conjunction operator, the disjunction expression, and one or more conjunctive conditions that precede the disjunction expression; receiving, in response to the determining, by the at least one processor, a restriction bitmap for each disjunction expression in the complex query expression, the restriction bitmap representing a set of rows that have satisfied the one or more preceding conjunctive conditions, wherein a bit from the restriction bitmap represents whether a respective row has satisfied the one or more preceding conjunctive conditions; determining whether respective cost savings justify restricting evaluation of each disjunctive condition from the plurality of disjunctive conditions using the restriction bitmap; responsive to determining that a disjunctive condition from the plurality of disjunctive conditions has a respective cost saving that justifies restricting evaluation, restricting, by the at least one processor, evaluation of the disjunctive condition to the set of rows represented by the restriction bitmap; and providing, by the at least one processor, a bitmap result of evaluating the disjunction expression, the bitmap result determined, in part, using the restricted evaluation of the disjunctive condition.
8. A non-transitory computer-readable storage device having instructions stored thereon, execution of which by a computing device, cause said computing device to perform operations comprising: determining, by at least one processor, a presence of a disjunction expression in a complex query expression, the disjunction expression including a disjunctive operator and a plurality of disjunctive conditions, wherein the complex query expression comprises a conjunction expression including a conjunction operator, the disjunction expression, and one or more conjunctive conditions that precede the disjunction expression; receiving, in response to the determining, by the at least one processor, a restriction bitmap for each disjunction expression in the complex query expression, the restriction bitmap representing a set of rows that have satisfied the one or more preceding conjunctive conditions, wherein a bit from the restriction bitmap represents whether a respective row has satisfied the one or more preceding conjunctive conditions; determining whether respective cost savings justify restricting evaluation of each disjunctive condition from the plurality of disjunctive conditions using the restriction bitmap; responsive to determining that a disjunctive condition from the plurality of disjunctive conditions has a respective cost saving that justifies restricting evaluation, restricting, by the at least one processor, evaluation of the disjunctive condition to the set of rows represented by the restriction bitmap; and providing, by the at least one processor, a bitmap result of evaluating the disjunction expression, the bitmap result determined, in part, using the restricted evaluation of the disjunctive condition. 9. The non-transitory computer-readable storage device of claim 8 , said operations further comprising: comparing said cost savings against a cost of additional bitmap operations before performing said restricting.