JP3568062B2 - Document database management device and document database management method - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a document database management apparatus and a document database management method for managing electronic documents.
[0002]
[Prior art]
Since an electronic document created by a word processor or the like is expressed as digital data, editing such as addition, deletion, and modification can be easily performed, and document creation efficiency can be improved. In addition, by constructing a document database device by storing a plurality of electronic documents in a large-capacity storage device, a target document can be electronically searched by a keyword search or the like.
[0003]
In a conventional document database management apparatus that manages electronic documents, when searching for a document, the document data itself created by a word processor or the like is stored, and the search is performed using the data.
[0004]
On the other hand, in order to facilitate creation and editing of electronic documents, electronic documents have been structured. The structure of a document is represented, for example, by information on elements such as chapters, headings, and paragraphs that make up the document and the relationship between the elements.For example, a chapter has information on headings and paragraphs as substructures. You.
[0005]
[Problems to be solved by the invention]
The problem to be solved by the present invention will be described by way of an example of ODA (Office Document Architecture) (ISO 8613) and SGML (Standard Generalized Markup Language) (ISO 8879; JIS X4151) which are international standards of document structure.
[0006]
First, terms used in the present specification will be described.
[0007]
The term “document structure” is an information structure representing a document. For example, the information structure defined by the ODA is a document structure. The SGML subsetting (restriction of functions) and the information structure used for a character code to be used or a chart are also a document structure. For details on SGML, see, for example, Martin Bryan, "Introduction to SGML", ASCII Corporation, issued on March 31, 1991.
[0008]
The term "document type" shall indicate a document template. The document type defines what logical structure a document created from it has, namely, the types of nodes appearing in the logical structure, the attributes that each node can have, and the substructure that each node can have. A common logical structure of the ODA and a document type definition (DTD) in a document architecture in which SGML is set are document types.
[0009]
Next, a description will be given of a problem in a case where a structured document is searched as described above.
[0010]
In a structured document, the content of the document is called a logical structure, and is represented by a tree structure including a plurality of document components such as chapters, sections, and figures. FIG. 10 shows an example of the logical structure.
[0011]
The logical structure is not completely free to be created, but is created according to the syntax rules called the document type described above. FIG. 11 shows an example of the document type. The rectangular node defines the element type (element type). The label of the node indicates the name of the element type. Nodes with the same name have the same element type. Therefore, the element type named “section” in FIG. 11 is defined recursively. Nodes indicated by ellipses define the connection of elements. This node is called a constructor. The SEQ node indicates that instances of the node connected to the SEQ node are generated in that order. The REP node indicates that the instance of the node connected to the REP node is generated one or more times. The OPT node indicates that the instance of the node connected to it may or may not appear. The CHO node indicates that an instance of any one node connected to the CHO node is generated. The logical structure of FIG. 10 satisfies the document type restriction of FIG.
[0012]
A document database management apparatus that manages structured documents provides a query language for describing a search. Some query languages are described in text, while others are described in a graphical user interface. FIG. 12 shows an example of a search expression described in the graphical user interface. The character string of the node indicates the element type. A character string shown beside a node indicates that the text of the node includes the character string. The arcs shown by solid lines indicate that the nodes at both ends are in a parent-child relationship. The arcs indicated by broken lines indicate that the nodes at both ends are in a grandchild relationship (a relationship between ancestors and descendants). When a plurality of arcs are emitted from one node, a search result that satisfies all conditions is obtained. That is, it is designated as a conjunction. The search formula in FIG. 12 specifies a search for “a chapter having a character string“ document ”in the headline and a paragraph including the character string“ database ””.
[0013]
The search formula is specified using a condition relating to the elements of the document and a condition relating to the connection relationship between the elements. In the example of FIG. 12, the former is a condition relating to the element type, and the latter is a condition using a grandchild relationship.
[0014]
FIG. 13 is a schematic diagram of a conventional database management device that performs the above-described search. The search expression created by the query editor 1 is converted by the search expression generation unit 2 into a search expression in a format executable by the search expression evaluation unit 3. This search expression searches for documents having elements that are passed to the document type management unit 5 and satisfy specified conditions. 6 is a data dictionary and 7 is a database. The search expression evaluation unit 3 also checks whether the search expression is grammatically correct. If the search expression is not grammatically correct, the operator is notified and the processing is stopped.
[0015]
In the conventional document database management apparatus shown in FIG. 13 which manages electronic documents, only a check is performed to determine whether a search expression is grammatically correct. For this reason, even if a search formula for which a solution cannot exist is given, it is treated as a correct search formula. For example, a search expression such as “a paragraph includes a character string“ database ”in a paragraph and a heading connected to the lower part of the paragraph includes a character string“ document ”” as shown in FIG. 14 is grammatically correct. No document has an element that satisfies this. That is, in the case of the structure of the document example shown in FIG. 11, a heading cannot exist below a paragraph.
[0016]
As a result of searching for such an invalid search expression, there is no search result that satisfies the condition, and nothing is obtained. From the user's point of view, the query is both grammatically and semantically correct, but it is not easy to determine whether anything in the database satisfies the condition or whether the query was invalid in the first place. This is a burden on the user when constructing the search formula. In addition, since a search process is performed even though a document having an element satisfying the condition cannot exist, the calculation time of the system is insignificantly wasted. The evaluation of the search expression shown in FIG. 14 typically scans all instances of headings and instances of paragraphs, and then checks whether there is something that satisfies the parent-child relationship. There is no need to evaluate because there can be no such thing.
[0017]
Therefore, an object of the present invention is to make it possible to easily determine the validity of a search expression. Another object of the present invention is to prevent a search time from being wasted on an invalid search expression, thereby preventing waste of calculation time.
[0018]
[Means for Solving the Problems]
In order to solve the above problem, the document database management apparatus of the present invention manages a structured document in which a structure that can be taken by a syntax rule defining a connection between elements is specified, and configures the structured document. In a document database management device that specifies a search target by a search formula using conditions relating to elements and conditions relating to parent-child relationships and grandchild relationships between the elements, syntax rules stored in the document database management device are given. Search expression verification means for collating the search expression, the search expression verification means, based on the syntax rules, as a parent starting element among the elements constituting the structured document, and as a child of the starting element and adjacent elements can appear, the the reachable elements that may appear as a descendant of the starting element and one group comprising the set of all the starting elements A correspondence table generation means for generating a correspondence table, based on the reachable elements starting element and the adjacent element in the given search expression, the abutment element and the reachable element for said starting element in the given search expression Means for scanning the correspondence table to verify whether or not it can appear, and verifying whether the search formula is valid.
[0019]
Further, the document database management method of the present invention includes a search expression verification unit and a correspondence table generation unit, and manages a structured document in which a structure that can be taken by a syntax rule that defines a connection between elements is specified as a management target. In a document database management apparatus for specifying a search target by a search formula using conditions relating to elements constituting a structured document and conditions relating to parent-child relationships and grandchild relationships between the elements, the search formula verification means includes: Based on the syntax rules in the device, a parent starting element, an adjacent element that can appear as a child of the starting element, and an arrival that can appear as a descendant of the starting element among the elements constituting the structured document possible elements as one set, a correspondence table with the set of all starting components generated by correspondence table generation unit, a given search expression Definitive based on the starting element and reachable and the adjacent Element to verify whether the above for the starting element and the adjacent elements the reachable elements in the given search expression may appear by scanning the correspondence table, It is characterized in that it is verified whether the search formula is valid.
[0020]
[Action]
According to the present invention, when a structured document is searched, a document type and a condition using a parent-child relationship and a grandchild relationship specified by the search formula are collated to determine whether the search formula is appropriate.
[0021]
In the present invention, a document type is checked before executing a search, and a parent starting element, an adjacent element that can appear as a child of the starting element among the elements constituting the structured document, A set of the reachable elements that can appear as descendants is generated, and a correspondence table including the above set for all starting elements is generated. When a search formula is input, the correspondence table is scanned based on the search formula, and it is determined whether the search formula satisfies the conditions of the correspondence table.If the condition is not satisfied, the search formula is invalid. Is determined.
[0022]
【Example】
FIG. 1 is a block diagram of the document database management device of the present invention. The query editor 1 is used to input search conditions and is input using a query editor screen as shown in FIG. The search expression created by the query editor 1 is converted by the search expression generation unit 2 into a search expression in a format executable by the search expression evaluation unit 3. This search expression is passed to the search expression verification unit 4, and it is determined whether the search expression is appropriate. Details of the processing in the search expression verification unit 4 will be described later. If it is a valid search expression, it is passed to the search expression evaluation unit 3 and searches for a document having an element satisfying the specified condition. 5 is a document type management unit, 6 is a data dictionary, and 7 is a database.
[0023]
The search expression verification unit 4 includes a verification control unit 8, a correspondence table holding unit 9, a correspondence table generation unit 10, and a reachability determination unit 11.
[0024]
The verification control unit 8 is an element that controls the whole, and appropriately calls the correspondence table holding unit 9, the correspondence table generation unit 10, and the reachability determination unit 11.
[0025]
The correspondence table holding unit 9 stores a triplet of an element (starting element), an element that can appear as a child of the starting element (adjacent element set), and a set of elements reachable from the starting element (reachable element set). Is held. Here, being reachable from an element A to an element B means that the element B can appear as a lower order (descendant) of an instance of the element A. FIG. 3 shows a correspondence table generated from the document type of FIG. For example, the element “article” is adjacent to “section” as a lower element, and the element “article” can reach any of the elements “section”, “headline”, and “paragraph”. It is shown that.
[0026]
The correspondence table generation unit 10 generates the above-described correspondence table with reference to the document type structure for the specified document type.
[0027]
When the two elements of the source and the destination are given, the reachability determination unit 11 scans the correspondence table (see FIG. 3) held in the correspondence table holding unit 9 and sets the entry having the source as the starting element. It is checked whether the destination is included in the neighboring element set or reachable element set. When a destination is included in the neighboring element set, the destination may appear as a child of the source. When the destination is included in the reachable element set, the destination may appear as a descendant of the source.
[0028]
4 to 9 show a flow of processing performed by the search expression verification unit 4 to verify a given search expression. The present embodiment will be described along this flow.
[0029]
FIG. 4 is an overall flow of verification of a search expression. The input of this processing is the search formula generated by the search formula generation unit 2. The verification control unit 8 calls the document type management unit 5 and acquires information on a schema (document type) to be searched for the input search expression (step 6-1). Subsequently, the correspondence table generation unit 10 is called to create a correspondence table of the schema (step 6-2).
[0030]
FIG. 5 is a flow of the correspondence table creation processing (see step 6-2 in FIG. 4). This processing is performed by the correspondence table generation unit 10. The input is schema information. Schema information is represented by a directed graph as shown in FIG. First, the root of the input schema is selected (step 7-2). Next, a set of element types that can be reached from the root is determined (step 7-3). The root is added to the set of element types reachable from the root to the variable S, and the set is held (step 7-4). The return value in step 7-4 indicates the result obtained by the immediately preceding process. Next, it is checked whether there is an unprocessed node in the variable S (step 7-5). If there is no unprocessed node, the process ends (step 7-10). If there is an unprocessed node, one is selected (step 7-6). A set of element types adjacent to the selected node is obtained (step 7-7). Further, a set of element types that can be reached from the selected node is obtained (step 7-8). The selected node (element type), the set of adjacent element types obtained in step 7-7, and the set of reachable element types obtained in step 7-8 are passed to the correspondence table holding unit 9 as a set of three. An entry is registered in the table (step 7-9). Thereafter, the process returns to step 7-5.
[0031]
FIG. 7 is a flow of a process for obtaining a reachable element type set (see step 7-3 in FIG. 5). This processing is also performed by the correspondence table generation unit 10. The input of this process is an element type, and the output is a set of element types that can be reached from the input element type. In this flow, a variable S that holds a set of element types and a variable Q that holds a queue of element types are used. The initial value of the variable S is an empty set (step 8-2). The initial value of the variable Q is a queue composed of all nodes adjacent to the input node (step 8-3). First, it is determined whether the length of the variable Q is 0 (step 8-4). If the length of the variable Q is 0, since a set of elements reachable from the input element type is stored in the variable S, the control is returned using this as a return value (step 8-10). If the length of the variable Q is 1 or more, the head element of the variable Q is extracted (step 8-11). If the extracted element is included in the variable S, the process returns to step 8-4. If the extracted element is not included in S, it is checked whether it is an element type (step 8-7). If it is an element type, the element type is added to S (step 8-8). All the nodes adjacent to the extracted element are added to the end of the variable Q (Step 8-9), and the process returns to Step 8-4.
[0032]
FIG. 8 is a flowchart of the process of obtaining the adjacent element type set (see step 7-7 in FIG. 5). This processing is also performed by the correspondence table generation unit 10. The input of this process is an element type, and the output is a set of element types adjacent to the input element type. Similar to the process of obtaining the reachable element type set, in this flow, a variable S holding an element type set and a variable Q holding an element type queue are used. The initial value of the variable S is an empty set (step 9-2). The initial value of the variable Q is a queue composed of all nodes adjacent to the input node (step 9-3). First, it is determined whether the length of the variable Q is 0 (step 9-4). If the length of the variable Q is 0, a set of elements that can be reached from the input element type is stored in the variable S, and control is returned using this as a return value (step 9-8). If the length of the variable Q is 1 or more, the head element of the variable Q is extracted (step 9-5). It is checked whether the fetched element is an element type (step 9-6). If it is an element type, the element type is added to the variable S (step 9-7), and the process returns to step 9-4. If it is not the element type, all nodes adjacent to the extracted element are added to the end of the variable Q (step 9-9), and the process returns to step 9-4.
[0033]
FIG. 9 is a flowchart of the verification processing of the nodes of the search expression (see step 6-4 in FIG. 4). This process is performed by the reachability determination unit 11. The input of this processing is a node of the search formula, and the output is a truth value indicating whether the node is valid or not. First, the correspondence table held in the correspondence table holding unit 9 is scanned, and an entry having the input node as a starting element type is obtained (step 10-2). Next, it is checked whether there is an unprocessed adjacent node (step 10-3). If all processes have been completed, the return value is set to true and control is returned (step 10-12). If there is an unprocessed adjacent node, one node is selected (step 10-4). It is determined whether or not the selected node is specified as a child of the input node (step 10-5). If it is specified as a child, it is checked whether the selected node is included in the adjacent element type set of the entry (step 10-7). If not, control is returned with the return value set to false (step 10-7). If it is included, the selected node is verified (step 10-8). In step 10-5, if the selected node is not specified as a child, that is, if it is specified as a descendant, it is checked whether the selected node is included in the reachable element type set of the entry (step 10-). 11). If not, control is returned with the return value set to false (step 10-13). If it is included, go to step 10-8. If the verification result in step 10-8 is false, the control is returned with the return value being false (step 10-10). If true, return to step 10-3.
[0034]
In the present embodiment, the correspondence table is formed every time the search expression is verified. However, the correspondence table may be formed when the document type is registered in the database, and the table may be scanned at the time of verification. .
[0035]
【The invention's effect】
As described above, according to the present invention, the document type and the condition using the parent-child relationship and the grandchild relationship specified by the search formula are collated, and it is determined whether the condition is appropriate.
[0036]
This makes it easy to determine whether a search result could not be obtained due to a semantic error in the search expression or whether there was no instance meeting the condition. In addition, the system does not need to evaluate a search expression in which a search result cannot be obtained, thereby preventing waste of calculation time.
[Brief description of the drawings]
FIG. 1 is a configuration of an embodiment of a document database management device of the present invention.
FIG. 2 is an example of a graphical user interface of a query editor.
FIG. 3 is an example of a correspondence table. This is the document type correspondence table shown in FIG.
FIG. 4 is a flowchart of verification of a search expression.
FIG. 5 is a flowchart of a correspondence table creation process.
FIG. 6 is a representation of the document type of FIG. 11 as a directed graph.
FIG. 7 is a flowchart of a process for obtaining a set of reachable element types from a certain element type.
FIG. 8 is a flowchart of a process for obtaining a set of element types adjacent to a certain element type.
FIG. 9 is a flowchart of a process of verifying a node of a search expression.
FIG. 10 is an example of a document instance.
FIG. 11 is an example of a document type. This is the document type of the document instance in FIG.
FIG. 12 is an example of specifying a search target.
FIG. 13 shows a configuration of a conventional document database management device.
FIG. 14 is an example of an invalid search expression. The document type used in this search formula is that of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Inquiry editor, 2 ... Search expression generation part, 3 ... Search expression evaluation part, 4 ... Search expression verification part, 5 ... Document type management part, 6 ... Data dictionary, 7 ... Database, 8 ... Verification control part, 9 ... Correspondence table holding unit, 10: Correspondence table generation unit, 11: Reachability judgment unit

Claims (2)

A structured document in which a structure that can be taken by a syntax rule that defines a connection between elements is defined as a management target, and conditions regarding elements constituting the structured document and conditions regarding a parent-child relationship and a grandchild relationship between the elements In a document database management device that specifies a search target by a search formula using
A search expression verification means for checking a given search expression with a syntax rule stored in the document database management device;
The search expression verification means, based on the syntax rules, includes a parent starting element, an adjacent element that can appear as a child of the starting element among elements constituting the structured document, and a descendant of the starting element. A correspondence table generating means for generating a correspondence table including the above sets for all the starting elements, with a set of the reachable elements that can appear, and a starting element and an adjacent element in the given search formula and reachable Based on the element , the correspondence table is scanned to verify whether the adjacent element and the reachable element can appear for the starting element in the given search expression, and whether the search expression is valid A document database management device comprising: A structured document that includes a search expression verification unit and a correspondence table generation unit, and a structure that can be taken by a syntax rule that defines a connection between elements is defined as a management target, and a condition regarding an element configuring the structured document; In a document database management device that specifies a search target by a search formula using a condition regarding a parent-child relationship and a grandchild relationship between the elements,
The search formula verification means , based on the syntax rules in the document database management device, a parent starting element among elements constituting the structured document, and an adjacent element that can appear as a child of the starting element, the reachable elements that may appear as a descendant of the starting elements as one set, a correspondence table with the set of all starting components generated by the corresponding table generation means, starting elements in a given search expression and Based on the adjacent element and the reachable element , the correspondence table is scanned to verify whether the adjacent element and the reachable element can appear for the starting element in the given search expression, and the search expression is A document database management method characterized by verifying validity.

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