Database theory—past and future
PODS '87 Proceedings of the sixth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Development of an object-oriented DBMS
OOPLSA '86 Conference proceedings on Object-oriented programming systems, languages and applications
Principles of database and knowledge-base systems, Vol. I
Principles of database and knowledge-base systems, Vol. I
A data model and query language for EXODUS
SIGMOD '88 Proceedings of the 1988 ACM SIGMOD international conference on Management of data
Identity, equality and query optimization
Lecture notes in computer science on Advances in object-oriented database systems
Optimization of object-retrieval queries
Lecture notes in computer science on Advances in object-oriented database systems
Query optimization in object-oriented database systems: A prospectus
Lecture notes in computer science on Advances in object-oriented database systems
Object identity as a query language primitive
SIGMOD '89 Proceedings of the 1989 ACM SIGMOD international conference on Management of data
Type systems for querying class hierarchies with non-strict inheritance
PODS '89 Proceedings of the eighth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
A model of queries for object-oriented databases
VLDB '89 Proceedings of the 15th international conference on Very large data bases
ILOG: declarative creation and manipulation of object identifiers
Proceedings of the sixteenth international conference on Very large databases
An object-oriented query algebras
Proceedings of the second international workshop on Database programming languages
Manipulation of structured values in object-oriented databases
Proceedings of the second international workshop on Database programming languages
A query language for the O2 object-oriented databases
Proceedings of the second international workshop on Database programming languages
Algebraic optimization of object-oriented query languages
ICDT '90 Proceedings of the third international conference on database theory on Database theory
On the equivalence of database restructurings involving object identifiers (extended abstract)
PODS '91 Proceedings of the tenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
The ObjectStore database system
Communications of the ACM
Introduction to object-oriented databases
Introduction to object-oriented databases
Object-oriented database systems
Proceedings of the seventh ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Extending the database relational model to capture more meaning
ACM Transactions on Database Systems (TODS)
Equivalences Among Relational Expressions with the Union and Difference Operators
Journal of the ACM (JACM)
Queries in Object-Oriented Databases
Proceedings of the Fourth International Conference on Data Engineering
Optimal implementation of conjunctive queries in relational data bases
STOC '77 Proceedings of the ninth annual ACM symposium on Theory of computing
Applying an update method to a set of receivers (extended abstract)
PODS '95 Proceedings of the fourteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Perspectives on database theory
ACM SIGACT News
Deciding containment for queries with complex objects (extended abstract)
PODS '97 Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
On the decidability of query containment under constraints
PODS '98 Proceedings of the seventeenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Query rewriting for semistructured data
SIGMOD '99 Proceedings of the 1999 ACM SIGMOD international conference on Management of data
Minimization of tree pattern queries
SIGMOD '01 Proceedings of the 2001 ACM SIGMOD international conference on Management of data
Applying an update method to a set of receivers
ACM Transactions on Database Systems (TODS)
Data integration: a theoretical perspective
Proceedings of the twenty-first ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Trigger Inheritance and Overriding in an Active Object Database System
IEEE Transactions on Knowledge and Data Engineering
View-Based Query Answering and Query Containment over Semistructured Data
DBPL '01 Revised Papers from the 8th International Workshop on Database Programming Languages
Description logics for semantic query optimization in object-oriented database systems
ACM Transactions on Database Systems (TODS)
Tree pattern query minimization
The VLDB Journal — The International Journal on Very Large Data Bases
Checking query containment with the CQC method
Data & Knowledge Engineering
Conjunctive query containment and answering under description logic constraints
ACM Transactions on Computational Logic (TOCL)
Revisiting redundancy and minimization in an XPath fragment
EDBT '08 Proceedings of the 11th international conference on Extending database technology: Advances in database technology
Type inference for datalog and its application to query optimisation
Proceedings of the twenty-seventh ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
How to decide query containment under constraints using a description logic
LPAR'00 Proceedings of the 7th international conference on Logic for programming and automated reasoning
Querying incomplete data with logic programs: ER strikes back
ER'07 Proceedings of the 26th international conference on Conceptual modeling
Semantic query optimization in the presence of types
Proceedings of the twenty-ninth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems
Querying incomplete data over extended er schemata
Theory and Practice of Logic Programming
Containment of conjunctive queries over conceptual schemata
DASFAA'06 Proceedings of the 11th international conference on Database Systems for Advanced Applications
Query containment in entity SQL
Proceedings of the 2013 ACM SIGMOD International Conference on Management of Data
Semantic query optimization in the presence of types
Journal of Computer and System Sciences
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With the availability of high-level declarative query languages in an object-oriented database system (OODB), the burden of choosing an efficient execution plan for a query is transferred from the user to the database system. A natural first step is to use the typing constraints imposed by the schema to transform a query into an equivalent one that logically accesses a minimal set of objects. We propose a class of queries called conjunctive queries for OODB's. A conjunctive query can be expressed as an equivalent union of queries in a special form called terminal conjunctive queries. We first characterize the containment, and hence equivalence, conditions for the class of terminal conjunctive queries. We then study a subclass of conjunctive queries called positive conjunctive queries. We characterize the containment and equivalence conditions, as well as derive an algorithm for finding an exact minimization for the class of positive conjunctive queries. The equivalent minimized query is expressed as a union of terminal positive conjunctive queries with the property that the variable search space is minimal among all the unions of postivie conjunctive queries.