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Constraint Query Languages
, 1992
"... We investigate the relationship between programming with constraints and database query languages. We show that efficient, declarative database programming can be combined with efficient constraint solving. The key intuition is that the generalization of a ground fact, or tuple, is a conjunction ..."
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Cited by 335 (35 self)
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We investigate the relationship between programming with constraints and database query languages. We show that efficient, declarative database programming can be combined with efficient constraint solving. The key intuition is that the generalization of a ground fact, or tuple, is a conjunction of constraints over a small number of variables. We describe the basic Constraint Query Language design principles and illustrate them with four classes of constraints: real polynomial inequalities, dense linear order inequalities, equalities over an infinite domain, and boolean equalities. For the analysis, we use quantifier elimination techniques from logic and the concept of data complexity from database theory. This framework is applicable to managing spatial data and can be combined with existing multidimensional searching algorithms and data structures.
Temporal Deductive Databases
, 1992
"... We survey a number of approaches to the problem of finite representation of infinite temporal extensions. Two of them, Datalog 1S and Templog, are syntactical extensions of Datalog; the third is based on repetition and arithmetic constraints. We provide precise characterizations of the expressivenes ..."
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Cited by 61 (9 self)
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We survey a number of approaches to the problem of finite representation of infinite temporal extensions. Two of them, Datalog 1S and Templog, are syntactical extensions of Datalog; the third is based on repetition and arithmetic constraints. We provide precise characterizations of the expressiveness and the computational complexity of these languages. We also describe query evaluation methods.
Constraint Programming and Database Query Languages
 In Proc. 2nd Conference on Theoretical Aspects of Computer Software (TACS
, 1994
"... . The declarative programming paradigms used in constraint languages can lead to powerful extensions of Codd's relational data model. The development of constraint database query languages from logical database query languages has many similarities with the development of constraint logic programmin ..."
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Cited by 60 (3 self)
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. The declarative programming paradigms used in constraint languages can lead to powerful extensions of Codd's relational data model. The development of constraint database query languages from logical database query languages has many similarities with the development of constraint logic programming from logic programming, but with the additional requirements of data efficient, setatatime, and bottomup evaluation. In this overview of constraint query languages (CQLs) we first present the framework of [41]. The principal idea is that: "the ktuple (or record) data type can be generalized by a conjunction of quantifierfree constraints over k variables". The generalization must preserve various language properties of the relational data model, e.g., the calculus/algebra equivalence, and have time complexity polynomial in the size of the data. We next present an algebra for dense order constraints that is simpler to evaluate than the calculus described in [41], and we sharpen some of...
Constraints and Redundancy in Datalog
 IN PROCEEDINGS OF THE ELEVENTH SYMPOSIUM ON PRINCIPLES OF DATABASE SYSTEMS (PODS
, 1992
"... Two types of redundancies in datalog programs are considered. Redundancy based on reachability eliminates rules and predicates that do not participate in any derivation tree of a fact for the query predicate. Redundancy based on irrelevance is similar, but considers only minimal derivation trees, ..."
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Cited by 33 (15 self)
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Two types of redundancies in datalog programs are considered. Redundancy based on reachability eliminates rules and predicates that do not participate in any derivation tree of a fact for the query predicate. Redundancy based on irrelevance is similar, but considers only minimal derivation trees, that is, derivation trees having no pair of identical atoms, such that one is an ancestor of the other. Algorithms for detecting these redundancies are given, including the case of programs with constraint literals. These algorithms not only detect redundancies in the presence of constraints, but also push constraints from the given query and rules to the EDB predicates. Under certain assumptions discussed in the paper, the constraints are pushed to the EDB as tightly as possible.
A Closed Form Evaluation For Datalog Queries With Integer (GAP)Order Constraints
 Theoretical Computer Science
, 1993
"... : We provide a generalization of Datalog based on generalizing databases by adding integer order constraints to relational tuples. For Datalog queries with integer (gap)order constraints (denoted Datalog !Z ) we show that there is a closed form evaluation. We also show that the tuple recognition ..."
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Cited by 27 (8 self)
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: We provide a generalization of Datalog based on generalizing databases by adding integer order constraints to relational tuples. For Datalog queries with integer (gap)order constraints (denoted Datalog !Z ) we show that there is a closed form evaluation. We also show that the tuple recognition problem can be done in PTIME in the size of the generalized database, assuming that the size of the constants in the query is logarithmic in the size of the database. Note that the absence of negation is critical, Datalog : queries with integer order constraints can express any Turing computable function. 1 Introduction In this paper we consider a generalization of Datalog based on the notion of a constraint tuple. The important idea of a constraint tuple comes from constraint logic programming systems, e.g. CLP [14], Prolog III [4], and CHIP [8], and it generalizes the notion of a ground fact. This allows the declarative programming of new applications, including various combinatorial se...
Safe Constraint Queries
 SIAM J. Comput
, 1998
"... ing with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications Dept, ACM Inc., fax +1 (212) 8690481, or permissions@acm.org. Safe Constraint Queries Michael Be ..."
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Cited by 27 (7 self)
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ing with credit is permitted. To copy otherwise, to republish, to post on servers, or to redistribute to lists, requires prior specific permission and/or a fee. Request permissions from Publications Dept, ACM Inc., fax +1 (212) 8690481, or permissions@acm.org. Safe Constraint Queries Michael Benedikt Bell Laboratories 1000 E Warrenville Rd Naperville, IL 60566 Email: benedikt@research.belllabs.com Leonid Libkin Bell Laboratories 600 Mountain Avenue Murray Hill, NJ 07974 Email: libkin@research.belllabs.com Abstract We extend some of the classical characterization theorems of the relational theory  particularly those related to query safety  to the context where database elements come with fixed interpreted structure, and where formulae over elements of that structure can be used in queries. We show that the addition of common interpreted functions such as real addition and multiplication to the relational calculus preserves important characterization theorems ...
Constraint Databases: A Survey
 Semantics in Databases, number 1358 in LNCS
, 1998
"... . Constraint databases generalize relational databases by finitely representable infinite relations. This paper surveys the state of the art in constraint databases: known results, remaining open problems and current research directions. The paper also describes a new algebra for databases with inte ..."
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Cited by 23 (3 self)
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. Constraint databases generalize relational databases by finitely representable infinite relations. This paper surveys the state of the art in constraint databases: known results, remaining open problems and current research directions. The paper also describes a new algebra for databases with integer order constraints and a complexity analysis of evaluating queries in this algebra. In memory of Paris C. Kanellakis 1 Introduction There is a growing interest in recent years among database researchers in constraint databases, which are a generalization of relational databases by finitely representable infinite relations. Constraint databases are parametrized by the type of constraint domains and constraint used. The good news is that for many parameters constraint databases leave intact most of the fundamental assumptions of the relational database framework proposed by Codd. In particular, 1. Constraint databases can be queried by constraint query languages that (a) have a semantics ba...
Domain Independence and the Relational Calculus
 Acta Informatica
, 1993
"... Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answe ..."
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Cited by 21 (7 self)
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Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answer to a relational calculus query is sometimes infinite (and hence not a relation). The following approaches which guarantee the finiteness of answers to queries are studied here: outputrestricted unlimited interpretation, domain independent queries, outputrestricted finite and countable invention, and limited interpretation. Of particular interest is the outputrestricted unlimited interpretation  although the output is restricted to the active domain of the input and query, the quantified variables range over the infinite underlying domain. While this is close to the intuitive interpretation given to calculus formulas, the naive approach to evaluating queries under this semantics calls ...
Database Programming with Delayed Updates
 IN INTL. WORKSHOP ON DATABASE PROGRAMMING LANGUAGES
, 1991
"... There are a variety of advanced database features which require the ability to manipulate "virtual" database states along with the actual stored state; examples of this include rulebased triggers in active databases, support for hypothetical reasoning, and some concurrent transaction processing s ..."
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Cited by 15 (8 self)
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There are a variety of advanced database features which require the ability to manipulate "virtual" database states along with the actual stored state; examples of this include rulebased triggers in active databases, support for hypothetical reasoning, and some concurrent transaction processing systems. This paper
Finite Queries do not Have Effective Syntax
, 1995
"... A relational query is called finite, or sometimes safe, iff it yields a finite answer in every database state. The set of finite queries of relational calculus is known to be unsolvable. However, in many cases it is possible to impose syntactical restrictions on the class of queries that guarantee f ..."
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Cited by 14 (3 self)
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A relational query is called finite, or sometimes safe, iff it yields a finite answer in every database state. The set of finite queries of relational calculus is known to be unsolvable. However, in many cases it is possible to impose syntactical restrictions on the class of queries that guarantee finiteness and do not reduce the expressive power of the calculus. We show that unfortunately this is not always the case, as we construct a recursive domain with decidable theory where any solvable (or enumerable, for that matter) subclass of queries either contains an infinite query, or misses a finite one. We show that although any domain can always be extended to a domain with an effective syntax for finite A preliminary version of this paper appeared in the Proc. of the 14th ACM SIGACTSIGMOD SIGART Symp. on Principles of Database Systems, San Jose, CA, May 2225, 1995. y This work has been partially supported by NSF Grant CCR 9403809. z A part of this research was carried out whil...