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18,751
Query optimization in heterogeneous DBMS
- In Proc. of VLDB, pp 277--91
, 1992
"... We propose a query optimization strategy for heterogeneous DBMSs that extends the traditional optimizer strategy widely used in commercial DBMSs to allow execution of queries over both known (i.e., proprietary) DBMSs and foreign vendor DBMSs that conform to some standard such as providing the usual ..."
Abstract
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Cited by 88 (0 self)
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We propose a query optimization strategy for heterogeneous DBMSs that extends the traditional optimizer strategy widely used in commercial DBMSs to allow execution of queries over both known (i.e., proprietary) DBMSs and foreign vendor DBMSs that conform to some standard such as providing the usual
DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases
, 1997
"... In semistructured databases there is no schema fixed in advance. To provide the benefits of a schema in such environments, we introduce DataGuides: concise and accurate structural summaries of semistructured databases. DataGuides serve as dynamic schemas, generated from the database; they are ..."
Abstract
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Cited by 572 (13 self)
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. We provide performance results based on our implementation of DataGuides in the Lore DBMS for semistructured data. We also describe the use of DataGuides in Lore, both in the user interface to enable structure browsing and query formulation, and as a means of guiding the query processor
Querying Heterogeneous Information Sources Using Source Descriptions
, 1996
"... We witness a rapid increase in the number of structured information sources that are available online, especially on the WWW. These sources include commercial databases on product information, stock market information, real estate, automobiles, and entertainment. We would like to use the data stored ..."
Abstract
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Cited by 724 (34 self)
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-featured database systems and can answer only a small set of queries over their data (for example, forms on the WWW restrict the set of queries one can ask). (3) Since the number of sources is very large, effective techniques are needed to prune the set of information sources accessed to answer a query. (4
NiagaraCQ: A Scalable Continuous Query System for Internet Databases
- In SIGMOD
, 2000
"... Continuous queries are persistent queries that allow users to receive new results when they become available. While continuous query systems can transform a passive web into an active environment, they need to be able to support millions of queries due to the scale of the Internet. No existing syste ..."
Abstract
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Cited by 584 (9 self)
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. Furthermore, grouping on selection predicates can eliminate a large number of unnecessary query invocations. Our grouping technique is distinguished from previous group optimization approaches in the following ways. First, we use an incremental group optimization strategy with dynamic re-grouping. New queries
The Lorel Query Language for Semistructured Data
- International Journal on Digital Libraries
, 1997
"... We present the Lorel language, designed for querying semistructured data. Semistructured data is becoming more and more prevalent, e.g., in structured documents such as HTML and when performing simple integration of data from multiple sources. Traditional data models and query languages are inapprop ..."
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Cited by 731 (29 self)
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are inappropriate, since semistructured data often is irregular, some data is missing, similar concepts are represented using different types, heterogeneous sets are present, or object structure is not fully known. Lorel is a user-friendly language in the SQL/OQL style for querying such data effectively. For wide
Answering Queries Using Views: A Survey
, 2000
"... The problem of answering queries using views is to find efficient methods of answering a query using a set of previously defined materialized views over the database, rather than accessing the database relations. The problem has recently received significant attention because of its relevance to a w ..."
Abstract
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Cited by 562 (32 self)
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wide variety of data management problems. In query optimization, finding a rewriting of a query using a set of materialized views can yield a more efficient query execution plan. To support the separation of the logical and physical views of data, a storage schema can be described using views over
Tinydb: An acquisitional query processing system for sensor networks
- ACM Trans. Database Syst
, 2005
"... We discuss the design of an acquisitional query processor for data collection in sensor networks. Acquisitional issues are those that pertain to where, when, and how often data is physically acquired (sampled) and delivered to query processing operators. By focusing on the locations and costs of acq ..."
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Cited by 626 (8 self)
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of acquiring data, we are able to significantly reduce power consumption over traditional passive systems that assume the a priori existence of data. We discuss simple extensions to SQL for controlling data acquisition, and show how acquisitional issues influence query optimization, dissemination
The design of an acquisitional query processor for sensor networks
- In SIGMOD
, 2003
"... We discuss the design of an acquisitional query processor for data collection in sensor networks. Acquisitional issues are those that pertain to where, when, and how often data is physically acquired (sampled) and delivered to query processing operators. By focusing on the locations and costs of acq ..."
Abstract
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Cited by 523 (25 self)
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of acquiring data, we are able to significantly reduce power consumption over traditional passive systems that assume the a priori existence of data. We discuss simple extensions to SQL for controlling data acquisition, and show how acquisitional issues influence query optimization, dissemination
Object exchange across heterogeneous information sources
- INTERNATIONAL CONFERENCE ON DATA ENGINEERING
, 1995
"... We address the problem of providing integrated access to diverse and dynamic information sources. We explain how this problem differs from the traditional database integration problem and we focus on one aspect of the information integration problem, namely information exchange. We define an object- ..."
Abstract
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Cited by 510 (55 self)
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-based information exchange model and a corresponding query language that we believe are well suited for integration of diverse information sources. We describe how, the model and language have been used to integrate heterogeneous bibliographic information sources. We also describe two general-purpose libraries we
Tractable reasoning and efficient query answering in description logics: The DL-Lite family
- J. OF AUTOMATED REASONING
, 2007
"... We propose a new family of Description Logics (DLs), called DL-Lite, specifically tailored to capture basic ontology languages, while keeping low complexity of reasoning. Reasoning here means not only computing subsumption between concepts, and checking satisfiability of the whole knowledge base, b ..."
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Cited by 497 (123 self)
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of the ABox (i.e., in data complexity). To the best of our knowledge, this is the first result of polynomial time data complexity for query answering over DL knowledge bases. Notably our logics allow for a separation between TBox and ABox reasoning during query evaluation: the part of the process requiring
Results 1 - 10
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18,751