KR100555982B1 - Information retrieval system for XML documents, its implementation methods, and the storage media containing program sources and the methods thereof - Google Patents

Abstract

The present invention provides an information retrieval system for an XML document, and a method and method for converting the document into a fragmented XML document having a hierarchical structure while maintaining the hierarchical structure of the XML document written in the extended markup language. An object of the present invention is to provide a computer-readable recording medium having recorded thereon a program.

In order to achieve the above object, the present invention provides an information retrieval method for an XML original document written in an extended markup language (XML), (A) having a plurality of layers formed in a vertical structure and constitutes each layer The plurality of nodes are converted into an XML original document having a tree structure, the XML original document having a plurality of change nodes forming a flat tree structure, (B) the XML modified document converted by the step (A) (C) retrieving the change node having desired information from among the information described in the XML change document stored in the (B) step; and (D) the change node retrieved by the step (C). Characterized in that it comprises the step of outputting corresponding to the hierarchical tree structure of the original document.

By the above configuration, the present invention enables to manage the XML document while maintaining the structural information of the original document without losing the structural information of the XML document, to help efficient query processing and to enable quick structure search, the search results Has the effect of providing the user with a three-dimensional search results.

XML source document, XML change document, hierarchy, fault, tree structure, DTD, fragmentation algorithm

Description

Information retrieval system for documents written in the extended markup language, and a computer readable recording medium recording the method therefor and a program for executing the method.Information retrieval system for XML documents, its implementation methods, and the storage media containing program sources and the methods

1 is an overall configuration diagram of an information retrieval system for an XML document according to an embodiment of the present invention.

2 is a detailed flowchart of an information retrieval method for an XML document according to an embodiment of the present invention.

3 is a detailed flowchart of a step of converting an XML original document of FIG. 2 into an XML modified document.

4 is a detailed flowchart of a step of storing the XML change document of FIG. 2.

FIG. 5 is a detailed flowchart of outputting the found change node of FIG. 2.

FIG. 6 is a diagram illustrating a path forming process of FIG. 5 in a tree structure.

<Explanation of symbols for major symbols in the drawings>

10: XML original document 20: Document Converter

30: XML change document 40: Document Saver

50: information search machine 60: structured search results output

The present invention relates to the storage and retrieval of information encoded in eXtensible Markup Language (XML). More specifically, the XML original document has a flat tree structure for efficient storage and retrieval of the XML original document. It is about converting and saving XML change document and searching for converted XML change document.

Modern computing systems can store, retrieve, and manage large amounts of data. However, computers are fast and efficient in handling numerical data, but are inefficient in manipulating text data and are particularly poor in translating human readable text data.

Thus, although it is possible to detect certain text strings or parts, such as words in an unidentified text document, it is not easy to locate a particular piece of information where the words have a particular meaning. For example, humans have no difficulty identifying the word 'will' in the sentence 'The attorney will read the text of Mark's will.', But computers generally do not.

Accordingly, techniques have been developed to help computers translate text documents by proper document coding. These techniques identify selected parts of a text document by adding document information, so-called 'markup tags', that identify parts of different documents in a way that allows the computer to reliably recognize the information. .

One of these languages is the so-called Standard Generalized Markup Language (SGML) and is internationally approved for the presentation of information. This language standard was made in the development of a general coding and markup language that was carried out in the early 1970s. Various research lines were merged into subcommittees of the International Standards Organization, the so-called text description and processing language. This subcommittee enacted the SGML Standard in 1986.

SGML itself is not a markup language in that it neither defines markup tags nor provides markup templates for certain types of documents. Instead, SGML shows how to describe and develop generalized description markup techniques. These techniques are generic because markup is not directed to a particular application and is technical because markup describes what the text represents instead of how it should be displayed. SGML is very flexible in that it allows users to define their own formats for documents, handle large and complex documents, and manage large information repositories.

Recently, SGML has proven to have many optional features that are not required for web-based applications and have a cost / benefit ratio that is not attractive to current vendors of web browsers. Thus, SGML is not commonly used and instead most documents on the web are stored and transmitted in markup language, so-called hypertext markup language or HTML.

HTML is a simple markup language based on SGML and is suitable for displaying small and fairly simple documents that are commonly transmitted over hypertext, multimedia, and the Web. It describes each part of the document using a small, fixed set of markup tags. A few fixed tags simplify the organization of the document and make the application much easier to build.

However, because the tags are fixed, HTML is not extensible and has very limited structure and validity. As electronic web documents become larger and more complex, it becomes increasingly clear that HTML does not have the capabilities required for large commercial publications.

In order to meet these large commercial publishing needs and enable new technologies for distributed document processing, industry so-called World Wide Web Consortiums have created other markup languages for applications that require more capabilities than those provided by HTML, The so-called extended markup language (XML) has been developed.

Like HTML, eXtensible Markup Language (XML) is a simplified subset of SGML designed specifically for Web applications and is easier to learn, use, and implement than full SGML. Unlike HTML, XML retains the advantages of SGML, which is extensibility, structure, and validity, but XML restricts the use of SGML constructs to ensure that defaults are valid when access to certain components of a document is not currently available over the Internet. .

In addition, XML defines how Internet Uniform Resource Locators can be used to identify component parts of XML documents.

An XML document consists of a series of entities or objects. Each entity may include one or more logical elements and each element may have any attribute or characteristic that describes how it is handled. XML provides a formal syntax to describe the relationships between the entities, elements, and attributes that make up an XML document. This syntax gives the computer how to recognize the component parts of each document.

XML uses paired markup tags to identify document components. In particular, the beginning and end of each logical element is clearly identified by the input of the start tag before the element and the end tag after the element. For example, tags <to> and </ to> can be used to identify the 'recipient' element of a document in the following manner.

document text ....... <to> Recipient </ to> ..... document text

The form and configuration of markup tags can be defined by the user, but is often defined by a trade association or similar entity to provide for interoperability between users. To operate with a certain set of tags, users need to know how markup tags are scoped from the normal text and the relationship between the various elements. For example, in an XML system, elements and their attributes are entered between matched pairs of angle brackets (<...>) and entity references begin with an ampersand and end with a semicolon (amp; ...;). Because XML tag sets are based on the logical structure of a document, it is not difficult to read and understand them. Since XML tag sets have different parts or components, certain tags are not practical for all elements of all documents. Instead, documents can be classified as 'types' with certain elements.

The Document Type Definition (DTD) indicates which element is expected to be a document type and indicates whether each element found in the document is allowed, allowed and required, or allowed but not required. Finally, by defining the role of each document element in the DTD, it is possible to check whether each element occurs at a valid location in the document. For example, the XML DTD allows a check to be made so that third level headings are not entered without the presence of second level headings. This hierarchical check cannot be done in HTML. The DTD for a document is typically inserted into the document header and each element is marked with an identifier such as <! ELEMENT>.

If the DTD is not available for the document, then the XML system defaults to elements that are not declared in the document because all or part of the DTD is not accessible over the Internet or the document author failed to generate the DTD. (default) Can assign a definition.

XML provides coding techniques that are flexible enough to describe any logical text structure such as letters, reports, notes, databases, or dictionaries.

However, there are some inefficiencies in storing XML documents written in XML, searching the contents of stored XML documents, and outputting search results.

XML documents generally have a hierarchical tree structure. Consequently, information retrieval for an XML document generally includes a search based on the contents of the XML document and a hierarchical structure of the XML document.

Query languages that support structure search such as XQuery can search the logical structure of the document, but do not consider the weight of the search results, and the content-based search method supports the ranking search applying the search result weight. It has a disadvantage that it is difficult to process a query for.

XML queries are generally based on a hierarchical tree structure of data contained in XML documents. In order to search such hierarchical tree structure, a query language such as XPath is used. In order to use the hierarchical tree structure, the user has to know exactly the hierarchical tree structure of XML data. In addition, in order to process an XML query expressed in XPath in an RDBMS, there is an inconvenience in that a fast connection algorithm for searching a hierarchical structure between objects is required.

The present invention has been devised to solve the above problems, and provides information for an XML document that is converted into a fragmented XML document having a flat structure while maintaining the hierarchical structure of the XML document written in the extended markup language. An object of the present invention is to provide a computer-readable recording medium having recorded thereon a retrieval system, a method thereof, and a program for executing the method.                         

The present invention also provides an information retrieval system for an XML document storing an XML document, a method for executing the method, and a computer for executing the method. It is another object of the present invention to provide a recording medium which can be read.

In addition, the present invention executes an information retrieval system and method and method thereof for an XML document that outputs the searched XML documents for the contents described in the fragmented XML documents corresponding to the tree structure of the XML document before fragmentation It is a further object to provide a computer readable recording medium having recorded thereon a program for the purpose of recording.

In order to achieve the above object, the present invention, in the information retrieval system for XML original document and has a plurality of hierarchical layers formed in the top and bottom structure in the information retrieval system for XML source documents A document converter for converting an XML original document having a tree structure into an XML change document having a flat tree structure, a document store for storing the XML change document converted by the document converter, and an XML change document stored in the document store. And an information searcher for searching for desired information among the information, and a structured search result outputter for outputting the result retrieved by the information searcher in correspondence with a hierarchical tree structure of the XML original document.

The document converter of the present invention is characterized in that it comprises a rule information device for designating a node group of nodes located in the same topology in the tree structure of the nodes included in the XML source document.

The rule information of the present invention is characterized in that it further comprises a level designator for specifying a level for each of the node group selected to be located at different stages in the tree structure.

The document converter of the present invention includes all of the XML source document through a top-down inspection starting with one or more top-level nodes included in the XML original document and ending with one or more bottom-most nodes. A searcher for checking whether each of the nodes is an element node belonging to the level, a searcher for searching for the first corresponding node first searched for an element node belonging to the level among the nodes by a top-down search, and one or more of the first corresponding node A first extractor for extracting structural information between an element node belonging to the level, a parent, a child, and a sibling among all subordinate nodes including the first relevant node when there is an element node belonging to the level among the lower nodes; An element node belonging to this level among one or more subnodes If present, a second extractor which extracts structure information between the first corresponding node, parent and sibling, and a tree structure of all nodes of the XML original document after the inspection by the searcher is finished for all nodes of the XML original document. It is characterized in that it comprises a sorter for arranging the element nodes belonging to at least one of the levels of all the nodes in a tree structure.

The document storage device of the present invention is characterized in that it is configured by the content of all or part of the element node of the XML original document, and further comprises an index index for storing the index corresponding to each of the levels.

The information searcher of the present invention is characterized in that it supports keyword type search.

The present invention relates to an information retrieval method for an XML original document written in an extended markup language (XML), comprising: (A) a plurality of nodes having a plurality of hierarchical layers and a plurality of nodes constituting each hierarchical tree; Converting the XML original document into an XML modified document in which a plurality of change nodes form a single tree structure, (B) storing the XML modified document converted by the step (A), (C) the ( Searching for the change node having desired information among the information described in the XML change document stored in step B), and (D) the change node retrieved by the step (C) in the hierarchical tree structure of the XML original document. Characterized in that configured to include the corresponding output step.

The XML original document of the present invention designates nodes located in the same topology in the tree structure among the nodes included in the XML original document as one node group, each of which is different in the tree structure. Characterized in that it is created by the Rule Document Type Definition (DTD) for specifying the level for each selected to be located in.

Step (A) of the present invention (a1) the XML source through a top-down inspection starting with the at least one top node provided in the XML source document and finishes for at least one lowest node Step 7 in which each of all nodes included in the document is an element node belonging to the level is searched. (A2) A search of the first relevant node first searched for an element node belonging to the level among the nodes by a top-down search. (A3) a structure between an element node belonging to the level and a parent, child, and sibling among all subordinate nodes including the first corresponding node when there is an element node belonging to the level among one or more subordinate nodes of the first corresponding node; (A4) an element node belonging to the level among one or more subordinate nodes of the first corresponding node is extracted; (A5) a tree structure of all nodes of the XML original document is maintained for all nodes of the XML original document, and if all the nodes are extracted And at least one element node belonging to the level is arranged in a tree structure.

Step (B) of the present invention includes the steps of storing the change nodes forming each of the tree structure of the XML change document converted by step (A), and the contents of all or part of the change node of the stored XML change document. An index consisting of an index characterized in that it comprises a step of storing.

The storing of the change node of the present invention may include storing structure information between the change node, a parent, a child, and a sibling, and storing the contents of the change node.

Step (C) of the present invention is characterized in that the search by the keyword method.

In the step (C) of the present invention, the content to be searched among the contents of the XML modified document is limited to one of the index indexes of the XML changed document, and the changed node is searched by searching for the limited contents. .

In the step (D) of the present invention, the nearest upper node of each change node is searched by (d1) starting from the found plurality of change nodes until reaching the highest change node in a bottom up manner. (D2) forming a path from the highest level change node of the XML change document to the retrieved change node by combining the searched higher node and the retrieved change node; and (d3) in the XML change document. Characterized in that it comprises a step of outputting all the path present.

The present invention provides a computer-readable recording medium recording a program for executing an information retrieval method for an XML original document written in an extended markup language (XML), comprising (A) a plurality of hierarchical layers. A process of converting a plurality of nodes constituting each hierarchy into an XML original document having a tree structure in which an XML original document has a plurality of change nodes forming a flat tree structure, and (B) converting by the step (A) A process of storing the modified XML change document, (C) a process of retrieving the change node in which the desired information is written among the information described in the XML change document stored in the step (B), and (D) the retrieved by the step (C). The change node is configured to include a process that is output corresponding to the hierarchical tree structure of the XML original document.

The XML original document of the present invention designates nodes located in the same topology in the tree structure among the nodes included in the XML original document as one node group, each of which is different in the tree structure. Characterized in that it is created by the Rule Document Type Definition (DTD) for specifying the level for each selected to be located in.

The process (A) of the present invention includes (a1) the XML source through a top-down inspection starting with one or more top-level nodes included in the XML source document and ending with one or more bottom-most nodes. A process of searching whether each of all nodes included in the document is an element node belonging to the level; (a2) a process of searching for the first corresponding node first searched for an element node belonging to the level among the nodes by a top-down search; (a3) When there is an element node belonging to the level among one or more subordinate nodes of the first corresponding node, the structural information between the element node belonging to the level and the parent, child, and sibling is included among all subnodes including the first relevant node. A process to be extracted, (a4) belonging to the level among one or more subnodes of the first corresponding node (A5) A tree structure of all the nodes of the XML original document is maintained for all nodes of the XML original document when the node is absent. An element node belonging to one or more of the above levels among all nodes is configured to include a process of arranging in a tree structure.

The process (B) of the present invention is a process in which change nodes constituting each tree structure of the XML change document converted by the process (A) are stored, and contents of all or part of the change nodes of the stored XML change document. An index consisting of an index characterized in that it comprises a process that is stored.

The process of storing the change node of the present invention is characterized in that it comprises a process of storing the structure information between the change node and the parent, child, sibling and the process of storing the contents of the change node.

The process (C) of the present invention is characterized by being searched by a keyword method.

The process (C) of the present invention is characterized in that the content to be searched among the contents of the XML modified document is limited to one of the index indexes of the XML modified document, and the changed node is searched by searching for the limited contents. .

The process (D) of the present invention (d1) starts with the searched plurality of change nodes and searches the nearest higher node of each change node until it reaches the highest change node in a bottom up manner. (D2) a process of forming a path from the highest level change node of the XML change document to the retrieved change node by combining the retrieved higher node and the retrieved change node; and (d3) to the XML change document. It is characterized in that all the existing paths are configured including the output process.

Hereinafter, with reference to the accompanying Figures 1 to 5 will be described a preferred embodiment of the present invention.

1 is an overall configuration diagram of an information retrieval system for an XML document according to an embodiment of the present invention.

Referring to FIG. 1, an XML original document 10 having a hierarchical tree structure exists and the XML original document 10 is converted into an XML change document 30 by the document converter 20. The XML change document 30 is stored in the document store 40 while reflecting the structural characteristics of the XML change document 30, and a user (not shown) who wants to retrieve information about the XML document may use the information retriever 50. Through the XML change document 30 to search for information to find. In addition, the information retrieved by the information searcher 50 is output by the structural search result outputter 60 according to the tree structure of the original XML original document 10.

2 is a detailed flowchart of an information retrieval method for an XML document according to an embodiment of the present invention.

Referring to FIG. 2, it can be seen that an information retrieval system for an XML document according to an embodiment of the present invention shown in FIG. 1 may be implemented as an information retrieval method for an XML document.

Referring to FIG. 2, it can be seen that the information retrieval method for an XML document according to an embodiment of the present invention has four steps.

The first step is to have a plurality of hierarchical hierarchical layers, and the plurality of nodes constituting each hierarchical structure is transformed into an XML original document having a tree structure and transformed into an XML modified document having a plurality of change nodes forming a single tree structure. The second step is a step (S20) of storing the XML change document converted by the step (A), the third step is from the information described in the XML change document stored in the step (B) In operation S30, the change node in which desired information is described is searched. Finally, the fourth step is a step (S40) in which the change node retrieved by the step (C) is output corresponding to the hierarchical tree structure of the XML original document.

2, the present invention converts an XML document into a fragmented XML document having a hierarchical structure while retaining hierarchical information about the hierarchical tree structure of the XML document (S10), and stores the fragmented XML document. By retrieving the information about the stored XML document (S20) and the user who does not know the exact information about the hierarchical tree structure of the original XML document, it is easier to retrieve the information contained in the XML document (S30), The searched result is an information retrieval method for outputting (S40) corresponding to the hierarchical tree structure of the original XML document.

The XML original document has a plurality of hierarchies formed in a hierarchical structure, and a plurality of nodes constituting each hierarchy has a tree structure. On the other hand, the XML source document is generally written in accordance with the grammar specified by the Rule DTD, and the Rule DTD defines the logic and physical structure of the XML source document as described above. More specifically, the XML source document is allowed in addition to the content model. Defines the element type to be defined, defines the attributes assigned to each element, defines the entities allowed in the XML source document, and defines the notation used with external entities.

Rule DTD used in the present invention is as follows.

<? xml version = "1.0" encoding = "iso-8859-1"?>

<! ELEMENT Rule (LevelInfo +)>

<! ELEMENT LevelInfo (TitleSection ?, IndexSectionList?)>

<! ATTLIST LevelInfo

no CDATA #REQUIRED

path CDATA #REQUIRED>

<! ELEMENT DisplaySection EMPTY>

<! ATTLIST DisplaySection

path CDATA #REQUIRED

type (SINGLE-TEXT | MULTI-TEXT | ALL) #REQUIRED

length CDATA #REQUIRED>

<! ELEMENT IndexSectionList (IndexSection +)>

<! ELEMENT IndexSection EMPTY>

<! ATTLIST IndexSection

name CDATA #REQUIRED

path CDATA #REQUIRED

type (SINGLE-TEXT | MULTI-TEXT | ALL) #REQUIRED>

Among the contents of the above rule DTD, LevelInfo is used to newly create a hierarchical relationship by specifying a level and has attributes of no and path. no means the level of the new element to specify and path means the name of the element to specify. DisplaySection is used as a quick view information of search results and has attributes such as path (designate element of output section), type (designate information extraction type of output section) and length (designate maximum length of output sentence). In addition, IndexSection is used to support indexing and searching for detailed elements within a node. It also specifies the name (name of the index section), path (name of the element in the index section), type (type of information extraction of the index section), and MULTI- TEXT means to extract all the text existing under the specified element, and SINGLE-TEXT means to extract only the text immediately below the specified element. ALL means to extract all the elements and text that exist below the specified element. Means to extract).

In one embodiment of the present invention, the Rule DTD specifies a level. Each layer of an XML source document generally has a tree structure, and each layer is in a superordinate relationship with each other. As a result, there is a vertical relationship between a plurality of nodes constituting a tree structure of a certain hierarchy and a plurality of nodes constituting a tree structure of another hierarchy, and in the light of the pattern of the tree structure, both nodes are located in the same phase. Nodes will exist. A plurality of nodes located in such a same phase and having different hierarchies are designated as one node group.

Although the number of nodes that make up a node group is plural, the XML source document can be treated as a non-hierarchical document with a tree structure if the node group is treated as one node. The Rule DTD selects some of the above node groups and assigns each to a level.

For example, in the XML original document, as shown in the XML original document 10 of FIG. 1, there are two hierarchies, and each hierarchical structure has the same three-level tree structure. The first stage is one node, and the second stage is four nodes. In step 3, assume that step 3 is a child of the second node of step 2. In this case, it can be seen that each of the two nodes among the total 14 nodes existing in the XML original document 10 have the same phase. For example, the phase 1 node of the upper layer and the level 1 node of the lower layer have the same phase, and the first node of the third level of the upper layer and the first node of the third level of the lower layer have the same phase.

If the tree structure of the upper hierarchy is composed of the node a1, the second stage is composed of the nodes b1, c1, d1, and e1, the third stage is composed of the nodes f1, g1, and h1, and the node of the third stage. All are subnodes of c1. In addition, the lower hierarchical tree structure consists of a node named a2, a second stage consisting of nodes b2, c2, d2, and e2, a third stage consisting of nodes f2, g2, and h2, and all three nodes Suppose is a subnode of c2. In this case, a1 and a2, b1 and b2, c1 and c2, d1 and d2, e1 and e2, f1 and f2, g1 and g2, h1 and h2 each have the same phase. In other words, in order to treat nodes of the same phase as one, the concept of a node group is introduced, and in the above example, the XML original document is a node group, b node group, c node group, d node group, e node group, and f node. It consists of a tree structure of group, g-node group, and h-node group, and does not have a plurality of hierarchies formed in a vertical structure.

Such a level is specified by the Rule DTD for each of each of the node families that make up the XML original document are selected to be located at different levels in the tree structure. For example, in the above example, level 1 and level 2 are designated for the a node group and the g node group, respectively. As a result, the a node group corresponding to the first stage of the tree structure is designated as level 1, and the b node group to the e node group correspond to the original tree structure and are subordinate to the a node group. In addition, the g-node group corresponding to the third stage of the tree structure is designated as level 2, and eventually, the node corresponding to the same stage as the g-node group under the c node group under the a node group in the tree structure composed of a plurality of node groups. Groups, i.e., the f-node group and the h-node group, correspond to level two.

As such, the Rule DTD specifies the level used when converting the XML original document into the fragmented XML modified document in one embodiment of the present invention before creating the XML original document as described above.

The XML original document is converted into an XML change document according to the level specified by the rule DTD (S10), the converted XML change document is stored (S20), the stored XML change document is searched (S30), and the searched result is an XML original document. It is arranged to match the hierarchical tree structure (S40) and the detailed appearance of each step will be described below.

3 is a detailed flowchart of a step of converting an XML original document of FIG. 2 into an XML modified document.

Referring to FIG. 3, it can be seen that the step S10 (see FIG. 2) of converting an XML original document into an XML modified document is largely composed of five steps. In an embodiment of the present invention, an algorithm for fragmenting an XML original document into an XML modified document is as follows.

Procedure FragmentAlgorithm (DOWNode parentNode, PathInfo ancestorPath, Integer parentRecordId, Integer firstChild)

Begin

DOWNodeList nodeList = parentNode.getChildNodes ();

RecordSet recordSet;

for (Integer i = 0, siblingOrder = 0 i <nodeList.getLength (); i ++) {

DOWNode node = nodeList.getNode (i);

if (node.getNodeType () == ELEMENT_NODE) {

Integer localFirstChild = 0;

PathInfo currentPath = makePath (ancestorPath, node);

if (RuleInformation.find (currentPath) == true) {

Record kristal Record;

FragmentAlgorithm (node, currentPath, Record.RECID, localFirstChild);

Record = getKristalInformation (node, currentPath, localFirstChild);

recordSet.store (kristalRecord);

siblingOrder ++;

if (siblingOrder == 1) firstChild = Record.RECID;

}

else {

FragmentAlgorithm (node, currentPath, parentRecordId, localFirstChild);

firstChild = localFirstChild;

}}}

End

The algorithm for making the XML change document is made up of 22 lines. As described above, the algorithm is made in five steps.

First, each of all nodes included in the XML source document is checked through a top down method that starts with one or more top-level nodes in the XML source document and ends with one or more bottom-most nodes. It is searched whether an element node belongs to the level specified in step S11. This searching step is an algorithm corresponding to 1 to 10 of the 22 lines. That is, the first line means bringing one child node of a node passed as a parameter one by one, and the fifth through seventh lines mean checking whether each node corresponds to an element node, and the nineth through tenth lines In the case of a node determined to be an element node, it means to check whether the node requests a fragmentation. The node requesting fragmentation means an element node belonging to the level. Furthermore, a node that requires fragmentation refers to a node that is a basic unit of a search service when searching for XML modified documents.

When the search step S11 is completed, the first corresponding node searched for the first element node belonging to the level among the nodes is searched through the top-down search (S12). That is, the search is performed from the top node to the lowest node in a top-down manner until an element node belonging to the level is found. After all, if an element node belonging to this level is not found while searching from the highest node to a certain higher node, the node continuously checks whether there is a node that requires fragmentation.

When the search step (S12) of the first relevant node is completed, the full fragmentation operation is not immediately performed. Once the first corresponding node is found (S12), it is determined whether there is an element node belonging to the level among the lower nodes of the first corresponding node (S13). This is an algorithm corresponding to 12 of the 22 lines.

As a result, if there is an element node belonging to the level among the lower nodes of the first corresponding node, the structural information between the element node belonging to the level, the parent, the child, and the sibling among all the descendant nodes including the first relevant node is extracted (S15). If there is no node requesting the fragmentation among the lower nodes of the first corresponding node, the structural information between the first corresponding node, the parent and the sibling is extracted (S14). This is an algorithm corresponding to 13 to 14 of the 22 lines. Meanwhile, the structure information extraction steps S14 to S15 extract and store not only the structure information but also information on title information, index information, level number, and type of element nodes belonging to all the levels existing in the XML original document. do.

After the structure information extraction step (S14 or S15) as described above, the tree structure of all nodes of the XML original document is maintained for all nodes of the XML original document and at least one belonging to the level among all the nodes. The element nodes are arranged in a tree structure (S16). In this case, each element node belonging to the level may include an attribute node or an element node not belonging to the level. Of course, the element nodes belonging to the level and the attribute nodes or element nodes not belonging to the level are respectively located in correspondence with the tree structure of the original XML original document. As a result, when the sorting step S16 is finished, the element node belonging to the level as described above, the attribute node belonging to the lower level, or the element node not belonging to the level are treated as one group and each Groups also have a tree structure. Of course, since the level is selected from the group of nodes, the XML original document that has completed the sorting step (S16) is converted into an XML modified document in which each group has a tree structure, but the upper and lower hierarchical structures are lost. The reason why the XML change document loses the hierarchical structure of the upper and lower parts is that the level is selected from the node group as described above, and the XML original document composed of the tree structure of the node groups has already lost the hierarchical structure of the upper and lower parts.

Eventually, the XML change document is the hierarchical tree structure by changing the hierarchical tree structure of the XML source document and rearranging the element nodes corresponding to the level specified by the Rule DTD into the tree structure. Document. The principle that the element nodes corresponding to the level are arranged in a tree structure is that the upper node and the lower node exist among all the element nodes belonging to the level existing in the XML original document, so that the order is arranged in the tree structure according to the structure information. Will be. Therefore, the details of the tree structure of each layer of the XML original document and the tree structure of the XML modified document may be different. However, since the tree structure of the XML modified document is derived from the tree structure of the XML original document, the XML modified document is XML Maintain structural information of the original document. Meanwhile, each group constituting each tree structure of the XML change document is referred to as a change node hereinafter.

4 is a detailed flowchart of a step of storing the XML change document of FIG. 2.

Referring to FIG. 4, it may be specifically understood that the XML change document generated by the XML document fragmentation algorithms S11 to S16 (see FIG. 3) is stored. That is, once the change node is stored (S21), an index index made up of the contents of all or part of the change node of the stored XML change document is stored for convenient retrieval (S30; see FIG. 2) (S22). . More specifically, the storage of the change node (S21) includes both the structure information storage between the parent, child, and siblings of the change node and the contents of the change node.

After the XML original document is converted into the XML change document according to the level specified by the Rule DTD (S10; see FIG. 2), the XML change document is stored as described above (S20; see FIG. 2), and the user (not shown) is stored. The content of the XML change document is queried and retrieved (S30; see FIG. 2). At this time, the basic unit of the search service is an element node belonging to the level. That is, if the element node belonging to the specific level is specified and the search is instructed, the contents of all subordinate change nodes including the specific change node having the specific node are retrieved. In particular, an embodiment of the present invention supports keyword search, and for this purpose, the index index S22 is required.

FIG. 5 is a detailed flowchart of outputting the found change node of FIG. 2.

When the search step S30 (see FIG. 2) is finished, the result of the searched change node is output (S40; FIG. 2). Referring to FIG. 5, it can be seen that the output step S40 (see FIG. 2) is largely composed of three steps.

First, one or more change nodes are searched as a result of performing the search step S30 (see FIG. 2). However, the searched change nodes may not form one path. In other words, it is not possible to know which path the specific subordinate change node retrieved is located along from the highest level change node. As a result, a situation arises in which the user (not shown) cannot structurally search the XML document only by outputting the changed change node immediately after the completion of the search step S30 (see FIG. 2). Therefore, the results of the retrieval step S30 (see FIG. 2) must be readjusted so that all of the retrieved one or more change nodes can see the path from the top change node according to the tree structure of the XML change document.

To this end, the present invention starts from the plurality of changed nodes searched by the searching step (S30; see FIG. 2) and reaches the closest of each changed node until reaching the highest change node in a bottom up manner. An upper node is searched (S41), and the searched upper node and the searched change node are combined to form a path from the highest level change node of the XML change document to the searched change node (S42). By outputting all the paths present (S43), the user (not shown) can check the structured search result for the XML change document. The search process (S41) of the upper node is made to correspond to the tree structure of the XML change document, and since the XML change document retains the structure information of the XML original document, the search process (S41) eventually results in the tree structure of the XML original document. It is output in correspondence with.

FIG. 6 is a diagram illustrating a path forming process of FIG. 5 in a tree structure.

Although already mentioned with reference to FIG. 5, the path forming step S42 (see FIG. 5) may be more schematically described with reference to FIG. 6. That is, as shown in (a) of FIG. 6, if the contents contained in the change nodes 2, 7, 8, 9, and 13 are found as a result of the search step S30 (see FIG. 5), the change nodes 7, 8, 9, 13 are detected. In this case, the user cannot know the structure of the XML source document as the path from the top-level change node 1 cannot be a structurally searched change node.

Accordingly, in the case of the change nodes 7, 8, 9, and 13, the upper node of each change node is searched in a bottom up manner until starting from each change node and reaching the highest change node 1. That is, in the change node 7, the change nodes 3 and 1 are searched, in the change node 8 and 9, the change node 4 is searched, and in the change node 13, the change nodes 6, 3 and 1 are searched (S41; see FIG. 5). .

Among the searched change nodes and searched change nodes, the parent node exists and the child node exists. Therefore, the node is arranged in a tree structure according to the structure information, and is combined to combine the path from the top-level change node 1 of the XML change document to the retrieved change node. Will be formed. That is, as shown in (b) of FIG. 6, a path consisting of change nodes 1-2-4-8, a path consisting of change nodes 1-2-4-9, a path consisting of change nodes 1-3-6-13, and a change A path consisting of nodes 1-3-7 is formed (S42; see FIG. 5).

All the paths thus formed are output (S43; see FIG. 5), so that the user sees a structured search result for the XML change document. On the other hand, since the XML change document maintains the structure information of the XML original document as it is, the user can perform a structural search for the XML original document through an embodiment of the present invention.

What has been described above is only one embodiment for implementing a computer-readable recording medium recording an information retrieval system for an XML document, a method thereof, and a program for executing the method according to the present invention. Without departing from the gist of the present invention as claimed in the following claims without being limited to the above embodiments, anyone of ordinary skill in the art to which the invention belongs will be able to carry out various changes.

The present invention enables to manage the XML document while maintaining the structural information of the original text without losing the structural information of the XML document, to help efficient query processing and to enable a quick structure search.

In addition, the present invention maintains the structural characteristics of the original text and outputs the search results for the XML document, thereby providing the user with a three-dimensional search result.

As a result, the present invention facilitates the management of documents having a large amount of structural information, such as ancient documents, reports, papers, e-books.

Claims (22)

In an information retrieval system written in Extended Markup Language (XML) for XML source documents, A plurality of nodes having a plurality of hierarchical layers and constituting each hierarchical structure comprises: a document converter for converting an XML original document having a tree structure into an XML change document having a single tree structure; A document store for storing the XML modified document converted by the document converter; An information searcher for searching for desired information among the information described in the XML change document stored in the document storage; And And a structured search result outputter configured to output a result retrieved by the information searcher in correspondence with a hierarchical tree structure of the XML original document. The method of claim 1, wherein the document converter, And a rule information group for designating nodes located in the same topology in the tree structure among the nodes included in the XML original document as one node group. The method of claim 2, wherein the rule information device, And a level designator for specifying a level for each of the node groups selected to be located at different stages in the tree structure. The method of claim 3, wherein the document converter, Each of all nodes included in the XML source document is included in the level through a top down test starting with one or more top level nodes included in the XML original document and ending with one or more lowest level nodes. A searcher for checking whether the element node belongs; A searcher for searching for the first corresponding node first searched by element nodes belonging to the level among the nodes by a top-down search; A first node for extracting structure information between an element node belonging to the level and a parent, a child, and a sibling among all subordinate nodes including the first corresponding node when there is an element node belonging to the level among one or more subordinate nodes of the first corresponding node; Extractor; A second extractor for extracting structure information between the first corresponding node, a parent, and a sibling when an element node belonging to the level among the one or more lower nodes of the first corresponding node does not exist; And Maintains the tree structure of all nodes of the XML original document after checking by all the nodes of the XML original document and arranges the element nodes belonging to the level of one or more of all the nodes in a tree structure. Information retrieval system for an XML document, characterized in that it comprises a sorter. The method of claim 4, wherein the document store, An information retrieval system for an XML document, characterized in that it further comprises an index index which is composed of the contents of all or part of the element nodes of the XML original document and stores an index corresponding to each of the levels. The method of claim 1, wherein the information retriever, An information retrieval system for an XML document, characterized in that it supports keyword type retrieval. In the information retrieval method for an XML original document written in Extended Markup Language (XML), (A) A plurality of nodes having a plurality of hierarchical layers and constituting each hierarchical structure are transformed into an XML original document having a tree structure and an XML original document having a plurality of change nodes forming a single tree structure. step; (B) storing the XML change document converted by the step (A); (C) searching for the change node in which the desired information is written among the information described in the XML change document stored in the step (B); And And (D) outputting the changed node retrieved by the step (C) in correspondence with a hierarchical tree structure of the XML original document. The method of claim 7, wherein The XML original document designates as one node group nodes among the nodes included in the XML original document in the tree structure, so that each of the node groups is located at different stages in the tree structure. An information retrieval method for an XML document, characterized in that it is created by a Rule Document Type Definition (DTD) specifying a level for each of the selected items. The method of claim 8, wherein step (A) is (a1) Each of all nodes included in the XML original document is inspected by a top down method starting with one or more topmost nodes included in the XML original document and ending with one or more lowest level nodes. Searching whether it is an element node belonging to the level; (a2) searching for the first corresponding node first searched for element nodes belonging to the level among the nodes by a top-down search; (a3) When there is an element node belonging to the level among one or more subordinate nodes of the first corresponding node, the structural information between the element node belonging to the level, the parent, the child, and the sibling among all the subnodes including the first relevant node is extracted. Becoming; (a4) extracting structural information between the first corresponding node, the parent, and the sibling when there is no element node belonging to the level among one or more subordinate nodes of the first corresponding node; And (a5) a tree structure of all nodes of the XML source document is maintained for all nodes of the XML original document, and the element nodes belonging to one or more levels of all the nodes are arranged in a tree structure. Information retrieval method for an XML document, characterized in that. The method of claim 7, wherein step (B) is Storing change nodes constituting each tree structure of the XML change document converted by step (A); And And storing an index of all or part of the changed nodes of the stored XML change document. The method of claim 10, wherein the storing of the change node comprises: Storing structure information between parents, children, and siblings of the change node; And Information retrieval method for an XML document, characterized in that it comprises the step of storing the contents of the change node. According to claim 7, wherein (C) step, An information retrieval method for an XML document, characterized by being searched by a keyword method. The method of claim 10 or 12, wherein step (C) is The information to be searched among the contents of the XML modified document is limited to one of the index indexes of the XML modified document, and the changed node is searched for the limited contents. The method of claim 7, wherein the step (D), (d1) searching for the nearest higher node of each change node starting from the searched plurality of change nodes until reaching the highest change node in a bottom up manner; (d2) forming a path from the highest level change node of the XML change document to the retrieved change node by combining the retrieved higher node and the retrieved change node; And (d3) an information retrieval method for an XML document, comprising the step of outputting all the paths existing in the XML change document. A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML original document written in Extended Markup Language (XML), (A) A plurality of nodes having a plurality of hierarchical layers and constituting each hierarchical structure are transformed into an XML original document having a tree structure and an XML original document having a plurality of change nodes forming a single tree structure. process; (B) a process of storing the XML change document converted by the step (A); (C) a process of searching for the change node in which the desired information is described among the information described in the XML change document stored in the step (B); And (D) the change node retrieved by the step (C) includes a process of outputting corresponding to the hierarchical tree structure of the XML original document. Computer-readable recording medium that records the program. The method of claim 15, The XML original document designates as one node group nodes among the nodes included in the XML original document in the tree structure, so that each of the node groups is located at different stages in the tree structure. A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML document, characterized by a Rule Document Type Definition (DTD) specifying a level for each of the selected items. The method of claim 16, wherein the (A) process, (a1) Each of all nodes included in the XML original document is inspected by a top down method starting with one or more topmost nodes included in the XML original document and ending with one or more lowest level nodes. Searching for whether an element node belongs to the level; (a2) a process of searching for the first relevant node first searched for element nodes belonging to the level among the nodes by a top-down search; (a3) When there is an element node belonging to the level among one or more subordinate nodes of the first corresponding node, the structural information between the element node belonging to the level, the parent, the child, and the sibling among all the subnodes including the first relevant node is extracted. Process; (a4) a process of extracting structural information between the first corresponding node, the parent, and the sibling when there is no element node belonging to the level among one or more subordinate nodes of the first corresponding node; And (a5) a tree structure of all nodes of the XML source document is maintained for all nodes of the XML source document, and the process includes the element nodes belonging to the level of one or more of all the nodes arranged in a tree structure. A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML document. The process of claim 15, wherein the process (B) A process of storing change nodes constituting each tree structure of the XML change document converted by the process (A); And A computer-readable recording program recording a program for executing an information retrieval method for an XML document, comprising a process of storing an index index consisting of all or a part of contents of a change node of the stored XML change document. media. The process of claim 18, wherein the change node is stored: A process of storing structure information between a parent, a child, and a sibling of the change node; And A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML document, comprising a process of storing the contents of the change node. The method of claim 15, wherein the (C) process, A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML document, characterized by being searched by a keyword method. The process of claim 18 or 20, wherein the (C) process, Executing the information retrieval method for the XML document, wherein the content to be searched among the contents of the XML change document is limited to one of the index indexes of the XML change document, and the changed node is searched for the limited content. A computer-readable recording medium that records a program for the program. The method of claim 15, wherein the (D) process, (d1) a process in which the closest upper node of each change node is searched starting from the found plurality of change nodes until reaching the highest change node in a bottom up manner; (d2) a process of forming a path from the highest level change node of the XML change document to the retrieved change node by combining the retrieved higher node and the retrieved change node; And (d3) A computer-readable recording medium having recorded thereon a program for executing an information retrieval method for an XML document, comprising a process of outputting all the paths present in the XML change document.

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