Answering XPath Queries over Networks by Sending Minimal Views (2004)
Keishi Tajima, Yoshiki Fukui, Ishikawa Japan
When a client submits a set of XPath queries to a XML database on a network, the set of answer sets sent back by the database may include redundancy in two ways: some elements may appear in more than...
Archiving Scientific Data (2002)
Buneman, Peter, Khanna, Sanjeev, Tajima, Keishi, Tan, Wang-Chiew
We present an archiving technique for hierarchical data with key structure. Our approach is based on the notion of timestamps whereby an element appearing in multiple versions of the database is...
Archiving Scientific Data (2002)
Peter Buneman, Sanjeev Khanna, Keishi Tajima, Wang-chiew Tan
We present an archiving technique for hierarchical data with key structure. Our approach is based on the notion of timestamps whereby an element appearing in multiple versions of the database is...
Query Language Constructs for Uncertain Query Patterns in Semistructured Data (2001)
Two main difficulties in specifying queries on semistructured data are structural heterogeneity of the data, and the lack of the schema in advance. In the languages proposed in past, wild cards are...
Cut as a Querying Unit for WWW, Netnews, and E-mail (2001)
Keishi Tajima, Yoshiaki Mizuuchiy, Masatsugu Kitagaway, Katsumi Tanaka
In this paper, we propose a query framework for hypertext data in general, and for WWW pages, Netnews articles, and e-mails in particular. In existing query tools for hypertext data, such as search...
Querying Composite Objects in Semistructured Data (2001)
In this paper, we propose an entity-based style of queries for semistructured data. First, we partition a semistructured data into subgraphs corresponding to real-world entities, in other words, into...
A Query Model to Synthesize Answer Intervals from Indexed Video Units (2001)
Sujeet Pradhan, Keishi Tajima, Katsumi Tanaka
While a query result in a traditional database is a subset of the database, in a video database, it is a set of subintervals extracted from the raw video sequence. It is very hard, if not impossible,...
Static Detection of Security Flaws in Object-Oriented Databases (2000)
Access control in function granularity is one of the features of many object-oriented databases. In those systems, the users are granted rights to invoke composed functions instead of rights to...
Discovery and Retrieval of Logical Information Units in Web (1999)
Keishi Tajima, Kenji Hatano, Takeshi Matsukura, Ryouichi Sano
In ordinary search engines for Web pages, the data unit for query processing is individual pages. Indexes are produced for each page in accordance with the words appearing in it. In actual Web data,...
Finding Context Paths for Web Pages (1999)
Yoshiaki Mizuuchiy, Keishi Tajima
The contents of Web pages are often not self-contained. A page author often assumes all the readers of the page come through the same path, and he sometimes omit the information described in the...
Finding Context Paths for Web Pages (1999)
Yoshiaki Mizuuchiy, Keishi Tajima
The contents of Web pages are often not self-contained. A page author often assumes all the readers of the page come through the same path, and he sometimes omit the information described in the...
Querying Composite Objects in Semistructured Data (1999)
In this paper, we propose an entity-based style of queries for semistructured data. First, we partition a semistructured data into subgraphs corresponding to real-world entities, in other words, into...
Querying Composite Objects in Semistructured Data (1998)
In this paper, we propose an entity-based style of queries for semistructured data. First, we partition a semistructured data into subgraphs corresponding to real-world entities, in other words, into...
Cut as a Querying Unit for WWW, Netnews, and E-mail (1998)
Keishi Tajima, Yoshiaki Mizuuchiy, Masatsugu Kitagaway, Katsumi Tanaka
In this paper, we propose a query framework for hypertext data in general, and for WWW pages, Netnews articles, and e-mails in particular. In existing query tools for hypertext data, such as search...
An Equational Object-Oriented Data Model and its Data-Parallel Query Language (1998)
Susumu Nishimura, Atsushi Ohori, Keishi Tajima
This paper presents an equational formulation of an objectoriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a...
Cut as a Querying Unit for WWW, Netnews, and E-mail (1998)
Keishi Tajima, Yoshiaki Mizuuchiy, Masatsugu Kitagaway, Katsumi Tanaka
In this paper, we propose a query framework for hypertext data in general, and for WWW pages, Netnews articles, and e-mails in particular. In existing query tools for hypertext data, such as search...
An Equational Object-Oriented Data Model and its Data-Parallel Query Language (1998)
Susumu Nishimura, Atsushi Ohori, Keishi Tajima
This paper presents an equational formulation of an objectoriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a...
Static Detection of Security Flaws in Object-Oriented Databases (1998)
Access control in function granularity is one of the features of many object-oriented databases. In those systems, the users are granted rights to invoke composed functions instead of rights to...
An Equational Object-Oriented Data Model and its Data-Parallel Query Language (1998)
Susumu Nishimura, Atsushi Ohori, Keishi Tajima
This paper presents an equational formulation of an objectoriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a...
An Equational Object-Oriented Data Model and its Data-Parallel Query Language (1996)
Susumu Nishimura, Atsushi Ohori, Keishi Tajima
This paper presents an equational formulation of an objectoriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a...
An Equational Object-Oriented Data Model and its Data-Parallel Query Language (1996)
Susumu Nishimura, Atsushi Ohori, Keishi Tajima
This paper presents an equational formulation of an objectoriented data model. In this model, a database is represented as a system of equations over a set of oid's, and a database query is a...
Static Detection of Security Flaws in Object-Oriented Databases (1996)
Access control in function granularity is one of the features of many object-oriented databases. In those systems, the users are granted rights to invoke composed functions instead of rights to...