S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....that is inspired by Xslt. It can for instance be used for transform ing Html documents or Xhtml documents which currently are available on the Web to well structured, semantically enriched Xml documents. 3. 1 A Prolog DOM for Xml We use association lists for representing complex objects, cf. [11]. This data structure is familiar to Lisp programmers. An association list consists of attribute value pairs of the form a i : v i , where a is an attribute and v i is the associated value. Thus, a complex object O, where v = O:a , 1 i n, can be represented as an association list O = a ....

D. Suciu, S. Abiteboul, P. Bunemann. Data on the Web { From Relations to Semi{Structured Data and Xml. Morgan Kaufmann, 2000.

.... descendant not illustrated above) is used to specify subterms at arbitrary depth. Query terms are unified with database or construct terms using a nonstandard unification called simulation unification, which has been investigated in [12] Simulation unification is based on graph simulation [13] which is similar to graph homomorphisms. The outcome of unifying a query term with a database term are bindings for the variables in the query term. Applying these bindings to the query term results in a ground query term which is simulated (in the sense of [13] in the database term. 5 ....

....is based on graph simulation [13] which is similar to graph homomorphisms. The outcome of unifying a query term with a database term are bindings for the variables in the query term. Applying these bindings to the query term results in a ground query term which is simulated (in the sense of [13]) in the database term. 5 Construct Terms serve to reassemble variable (the bindings of which are specified in query terms) so as to construct new database terms. They may only contain single brackets and variables, but no partial specification or variable restrictions. The rationale of this is ....

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000)

....Element class of the Document Object Model (DOM) This mechanism provides a generalization of a previous approach based on the weaker concept of Document Type Definitions presented by the authors. I. INTRODUCTION XML schemas [W3 01a] provide a generalization of Document Type Definitions (DTDs) ABS00] W3 98b] for describing the validity of a set of XML documents. There is a growing number of applications that deal with XML documents in various respects. One area of programs is concerned with analyzing XML documents arriving, for example, over the internet. Another rapidly expanding area is ....

....have to be found dynamically by appropriate test runs. Similar problems arise with other server page mechanisms like PHP [BAS 01] or Informix Webdriver [Inf97] or JAVA Script on the client side. In previous work [KL01] we addressed this problem on the basis of Document Type Definitions (DTDs) ABS00] W3 98b] In the meantime, DTDs are somewhat outdated because the capabilities of describing the document structure on the basis of regular expressions is rather limited. Nowadays, DTDs are being replaced by XML schemas [W3 01a] a mechanism which is much more general than DTDs and provides ....

[Article contains additional citation context not shown here]

Serge Abiteboul, Peter Buneman, and Dan Suciu. Data on the Web, From Relations to Semistructured Data and XML. Morgan Kaufmann Publishers, San Francisco, California, 2000.

....programming to reasoning on the Web. 2 Semistructured Expressions In contrast to the tuples of a relational database that are tree shaped, Web pages correspond to nested, possibly cyclic graphs. Abstracting from XML [1] and HTML [3] Web pages are conveniently formalised as semistructured data [6]. Semistructured data items are conveniently represented by semistructured expressions (short sse ) 6] that are defined by the following grammar: sse : oid )7 (label I label list ) list : ordered list I unordered list . ordered list : sse str ref ( sse str ref ) ....

....database that are tree shaped, Web pages correspond to nested, possibly cyclic graphs. Abstracting from XML [1] and HTML [3] Web pages are conveniently formalised as semistructured data [6] Semistructured data items are conveniently represented by semistructured expressions (short sse ) [6] that are defined by the following grammar: sse : oid )7 (label I label list ) list : ordered list I unordered list . ordered list : sse str ref ( sse str ref ) unordered list : sse str ref ( sse str ref ) sse str ref : sse I . string ....

[Article contains additional citation context not shown here]

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000)

....at arbitrary depth. Example: This query term selects titles and authors: bib book var T # title, authors var A 2 Query terms are unified with database or construct terms using a non standard unification called simulation unification [11] It is based on graph simulation [12] which is similar to graph homomorphisms. The outcome of unifying a query term with a database term are bindings for the variables in the query term. Applying these bindings to the query term results in a ground query term which is simulated (in the sense of [12] in the database term. The ....

....It is based on graph simulation [12] which is similar to graph homomorphisms. The outcome of unifying a query term with a database term are bindings for the variables in the query term. Applying these bindings to the query term results in a ground query term which is simulated (in the sense of [12]) in the database term. The Xcerpt construct X # t (read as ) serves to associate a query term to a variable, so as to specify a restriction of its bindings. The Xcerpt construct desc (read descendant not illustrated above) is used to specify subterms at arbitrary depth. Construct terms ....

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000) 4

....the markup language for the presentation of hypertext content on mobile phones. Section 5 gives some implementation details, section 6 concludes the paper. 2 Validating Object Model This section presents the basic concepts of XML, DOM and its extension V Dom. An introduction to XML is given in [1] and the idea of V Dom is described in detail in [14] Documents in XML mainly consist of elements. Elements are enclosed by start tags and end tags. Elements are nested and a distinguished root element always contains the whole document. The content of an element can be a nested structure or ....

Serge Abiteboul, Peter Buneman, and Dan Suciu. Data on the Web, From Relations to Semistructured Data and XML. Morgan Kaufmann Publishers, San Francisco, California, 2000.

....terms. Then, Xcerpt and XQuery are compared on examples and the advantages of Xcerpt are discussed. Finally, an outlook into Xcerpt s declarative and procedural semantics as well as into Xcerpt s features currently developed are given. 1 Introduction Essential to semistructured data [1] is the selection of data from incompletely specified data items. For such a data selection, a path language such as XPath [2] is convenient because it provides constructs similar to regular expressions such as #, and wildcards that give rise to a flexible node retrieval. For example, ....

....than an XML format for Xcerpt queries. Furthermore, the requirements of [8] are fulfilled by Xcerpt. 3 Basic Constructs of Xcerpt 3.1 Database Terms Database terms are XML documents in a simplified syntax. Following a common practice in XML query language and semistructured data research [1], the children of a document node may be either ordered (as in SGML and in standard XML) or unordered (as in semistructured data) A database is an XML document or a set (or multiset) of XML documents. Example 2. The following database term with root labelled bib describes the book o#ers of an ....

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000)

....schema (expressed in XML in the DTD or XML Schema formalisms) This principle aims at facilitating the interchange of data in unnormed contexts like the World Wide Web. XML like tree structured data items that do not necessarily conform to a schema are called semistructured in database research [3]. Query languages [4] inspired from SQL and OQL [5] have been developed for XML and semistructured data. Queries in these languages for XML and semistructured data in general consist of two parts: a query proper and a construct part. The query part expresses a selection of nodes (i.e. subterms) ....

....or without indices and or superscripts) are used: l denotes a label, X denotes a variable, t denotes a term (as defined below) 2.1 Database Terms Database terms are an abstraction of XML documents. Following a common practice in XML query language and semistructured data research [3], a database is a set (or multiset) of database terms and the children of a document node may be either ordered (as in SGML and in standard XML) or unordered (as in the semistructured data model) In the following, a term whose root is labelled l and has ordered children t 1 , t n is ....

[Article contains additional citation context not shown here]

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML . Morgan Kaufmann Publishers, San Francisco, CA (2000)

....schema (expressed in XML in the DTD or XML Schema formalisms) This principle aims at facilitating the interchange of data in unnormed contexts like the World Wide Web. XML like tree structured data items that do not necessarily conform to a schema are called semistructured in database research [3]. Query languages [4] inspired from SQL and OQL [5] have been developed for XML and semistructured data. Queries in these languages for XML and semistructured data in general consist of two parts: a query proper and a construct part. The query part expresses a selection of nodes (i.e. subterms) ....

....or without indices and or superscripts) are used: l denotes a label, X denotes a variable, t denotes a term (as defined below) 2.1 Database Terms Database terms are an abstraction of XML documents. Following a common practice in XML query language and semistructured data research [3], a database is a set (or multiset) of database terms and the children of a document node may be either ordered (as in SGML and in standard XML) or unordered (as in the semistructured data model) In the following, a term whose root is labelled l and has ordered children t 1 , t n is ....

[Article contains additional citation context not shown here]

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML . Morgan Kaufmann Publishers, San Francisco, CA (2000)

....term and D a database. An answer to t in D is a database term t D such that there exists an allowed ground instance t of t satisfying t . 3. 1 Concluding Remarks In previous works, simulation has been used for verifying the conformity of semistructured data to a schema cf. e.g. [5,6]. Here, it is used for query answering. The authors are not aware of former uses of simulation for query answering. 7] describes a language called fxt that has variables for terms, corresponding to trees, and forests. In fxt, node selection is done with regular expressions. In contrast to xcerpt ....

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000)

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

No context found.

Serge Abiteboul, Peter Buneman, and Dan Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

....problems were studied in the absence [21] and presence [20] of DTDs. The keys considered there are defined in terms of XML attributes and are not as expressive as keys studied in this paper. 2 Integrity constraints defined in terms of navigation paths have been studied for semistructured [3] and XML data in [5, 14, 15, 16] These constraints are generalizations of inclusion dependencies commonly found in relational databases, and are not capable of expressing keys. Generalizations of functional dependencies have also been studied [23, 26, 33] However these generalizations were ....

....to itself. The transition diagrams of M(P ) and M(Q) can be treated as graphs in which each edge is labeled with a letter in C [ f g. Given the edge labeled graphs, we define a simulation relation, Delta, on N 1 Theta N 2 . Similar to simulations exploited in the context of semistructured data [3], the relation Delta defines a correspondence between the nodes (or edges) in M(P ) and M(Q) such that any string that is accepted by M(P ) is also accepted by M(Q) according to the simulation relation. More specifically, for any n 1 2 N 1 and n 2 2 N 2 , n 1 Delta n 2 iff the following ....

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

....problems were studied in the absence [22] and presence [21] of DTDs. The keys considered there are de ned in terms of XML attributes and are not as expressive as keys studied in this paper. 2 Integrity constraints de ned in terms of navigation paths have been studied for semistructured [3] and XML data in [5, 15, 16, 17] These constraints are generalizations of inclusion dependencies commonly found in relational databases, and are not capable of expressing keys. Generalizations of functional dependencies have also been studied [24, 27, 34] However these generalizations were ....

....a state back to itself. The transition diagrams of M(P ) and M(Q) can be treated as graphs in which each edge is labeled with a letter in C [ f g. Given the edge labeled graphs, we de ne a simulation relation, on N 1 N 2 . Similar to simulations exploited in the context of semistructured data [3], the relation de nes a correspondence between the nodes (or edges) in M(P ) and M(Q) such that any string that is accepted by M(P ) is also accepted by M(Q) according to the simulation relation. More speci cally, for any n 1 2 N 1 and n 2 2 N 2 , n 1 n 2 i the following conditions are satis ....

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufman, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu, Data on the web. From relations to semistructured data and xml, Morgan Kaufmann Publishers, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web { from relations to semistructured data and XML. Morgan Kaufann, San Francisco, CA, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann, 2000.

No context found.

Serge Abiteboul, Peter Buneman, and Dan Suciu. Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann, 2000.

No context found.

S. Abiteboul, P. Buneman, and D. Suciu. From Relations to Semistructured Data and XML. Morgan Kaufmann Publishers, San Francicso, California, 2000. 1-55860-622-X.

No context found.

Serge Abiteboul, Peter Buneman, and Dan Suciu, Data on the Web, From Relations to Semistructured Data and XML, Morgan Kaufmann Publishers, San Francisco, California, 2000.

No context found.

Serge Abiteboul, Peter Buneman, and Dan Suciu. Data on the Web, From Relations to Semistructured Data and XML. Morgan Kaufmann Publishers, San Francisco, California, 2000.

No context found.

Abiteboul, S. / Buneman, P. / Suciu, D. (2000): Data on the Web. From Relations to Semistructured Data and XML.

No context found.

Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web. From Relations to Semistructured Data and XML. Morgan Kaufmann (2000)

First 50 documents

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC