Naughton, J. F., Ramakrishnan, R., Sagiv, Y., Ullman, J. D.: E#cient Evaluation of Right-, Left-, and Multi-Linear Rules. SIGMOD Conf. 1989: 235-242.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....queries against s b . As each negative (derived) literal causes a separate function call, many facts are repeatedly computed in the example above. In addition this separation of context makes it difficult or even impossible to apply further rule optimization techniques as proposed, e.g. in [13, 14]. Of course, for finite Herbrand universes and fixed rule sets, any of the above mentioned approaches requires time polynomial in the size of the Herbrand universe. The actual e#ciency therefore strongly depends on the chosen implementation and the applied optimization techniques. The discussion ....

Naughton, J. F., Ramakrishnan, R., Sagiv, Y., Ullman, J. D.: E#cient Evaluation of Right-, Left-, and Multi-Linear Rules. SIGMOD Conf. 1989: 235-242.

....against those of previous methods. 1 Introduction Several strategies has been proposed for the optimization of bound Datalog queries. Most of these strategies rewrite the original program into a queryequivalent new program which can be evaluated more e#ciently by the seminaive algorithm [2, 14, 4, 3, 9, 10, 12]. The improved e#ciency of the rewritten program is due to the fact that it restricts the search to the portion of the underlying database that is relevant to the query. Other techniques present special algorithms that compute directly the original program [7, 17, 1, 6, 18] Rewriting based ....

....to their generality. Techniques that can be applied to all programs include the magic set method and the supplementary magic set method [2, 4] Specialized techniques include the factorization and reduction of programs [9] the combination of the propagation of bindings with a successive reduction [10], and the counting method [2, 13, 1, 6] These specialized techniques are important, since many programs of practical interest contain only linear recursive rules, to which these techniques apply, yielding an order of magnitude improvement in e#ciency [16] Comparisons between the magic set method ....

J. Naughton, R. Ramakrisnhan, Y. Sagiv, J.F. Ullman. E#cient evaluation of right-, left-, and multi-linear rules. In Proc. of the SIGMOD Conf., 1989.

.... database applications over the traditional top down approaches [31] The e#ectiveness of the bottom up execution for bound queries is based on optimizations techniques that transform the original program into an equivalent one that e#ciently exploits bindings during fixpoint based computation [5, 6, 8, 14, 22, 23, 26, 31]. These rewriting techniques give the bottom up computation a wider applicability range than the top down computation typical of Prolog, and have been used successfully in several deductive database prototypes. As discussed next, however, there still remains room for major extensions and ....

....method is that it introduces a unified framework for the treatment of special cases, such as the factorization of right , left , mixed linear programs, as well as the linearization of non linear programs. A number of specialized techniques for the above special cases are known in the literature [16, 17, 22, 23, 30, 35, 37]. Given the importance and frequency of these special situations in practical applications, novel deductive systems call for the usage of a unique method that includes all advantages of the various specialized techniques. 1.3. Related work The analogies between chain queries and context free ....

J. Naughton, R. Ramakrisnhan, Y. Sagiv, and J.F. Ullman. E#cient evaluation of right-, left-, and multi-linear rules. In Proceedings of the 1988 ACM SIGMOD Conference, 1989, pages 235--242.

....linear ones. 1 Introduction In the last decade bottom up evaluation of logic programming has been favored by deductive database applications over traditional top down approaches [18] The e#ectiveness of the bottom up execution for bound queries is based on optimizations techniques [4, 6, 10, 13, 14, 16, 18] that transform the original program into an equivalent one that e#ciently exploits bindings during fixpointbased computation. These rewriting techniques give the bottom up computation a wider applicability range than the top down computation typical of Prolog, and have been used successfully in ....

....is that it introduces a unified framework for the treatment of special cases, such as the factorization of right , left , mixed linear linear programs, as well as the linearization of non linear programs. A number of specialized techniques for the above special cases are known in the literature [13, 14, 23]. Given the importance and frequency of these special situations in practical applications, novel deductive systems call for the usage of a unique method that includes all advantages of the various specialized techniques. We point out that analogies between chain queries and context free ....

J. Naughton, R. Ramakrisnhan, Y. Sagiv, and J.F. Ullman. E#cient evaluation of right-, left-, and multi-linear rules. In Proc. SIGMOD Conf., 1989, pages 235--242.

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