Scheme for constructing database for user system from structured documents using tags6973458Abstract A scheme for constructing a database in a user system, which can automatically store those portions of the structured documents which contain important contents without exerting a burden on the user is disclosed. A structured document provided by a server device is obtained according to a document request made by the user system, where each structured document has a structure represented by tags in each structured document. Then, at least one important portion is automatically extracted from the structured document by utilizing the structure of the structured document according to prescribed extraction criteria specified in advance, and the extracted important portion is stored into the database, while the obtained structured document is transferred to the user system. Claims 1. A method of constructing a database specific to a user system and related to structured documents that are utilized by the user system, each structured document having a structure represented by tags and being provided from a server device, the method comprising the steps of: Description BACKGROUND OF THE INVENTION
Also, there are some structured documents which are capable of being related to a document called DTD (Document Type Definition) that defines the document structure. The DTD defines types of tags that can be used in the structured document, a hierarchical relationship among these tags, etc., so as to clearly define the logical structure of the structured document. First Embodiment Referring now to FIG. 1 to FIG. 17, the first embodiment of the database construction scheme according to the present invention will be described in detail. In this first embodiment, a document important item extraction device is provided with a function for specifying one or a plurality of "important items", and a function for identifying each important item by attaching arbitrary name and enabling specification of one or a plurality of extraction methods for each important item. Here, the specification of "important item extraction method" is made by specifying "tag name" or "word" of the structured document. In the document important item extraction device of this first embodiment, when the specified tag name or word is contained in the structured document, the entire structured document or only the specified tag portion of the structured document is stored. In the case of analyzing the structured document, the document structure is already structured by the tags, so that it can be analyzed easily by using the tags. Even in the case of determining a range of the extracted important items, it can be easily determined by setting the entire tags containing the important items as this range. For this reason, it can be said that the extraction processing load is very light. In this way, it becomes possible to store only the important items or the structured documents that contain the important items from many structured documents effectively. In addition, a data transmission and reception device (client device) is provided with a function for explicitly displaying portions extracted and stored by the document important item extraction device at a time of displaying the structured document. In this way, it becomes possible for the user to easily identify the important items in the structured document. On the contrary, when some important item is not displayed as such, it can be confirmed by the user that the document important item extraction device has failed the extraction of that important item. As a method for explicitly displaying the important items, there are various methods available, including that for displaying the important items in a color different from colors of other characters used in the document, or that for displaying the important items in a color different from colors of other backgrounds used in the document. The data transmission and reception device of this first embodiment is provided with a function for explicitly specify, add, change or delete portions to be automatically extracted and stored by the document important item extraction device. For example, a portion corresponding to the important item is specified to the document important item extraction device by specifying a region in the structured document using a position specifying device (pointing device) such as mouse. Also, when there is an item which has the same meaning as the other important item, this item is added as the important item. Else, when there is an item among those items which are specified as the important items which is later judged as not an important item, a change is made so as not to extract this item as the important item. Also, when a portion which is explicitly displayed as an important item by the data transmission and reception device is actually not an important item, the user can specify the deletion of the automatic extraction function for the corresponding portion. In this way, the user can easily realize the specification, addition, change and deletion of the important items. In the case of specifying the important item, a "telephone" tag in the structured document can be specified by the important item "telephone number", for example. In the case where a tag "TEL" is also an important item expressing the telephone number similarly, a tag "TEL" is added to the important item "telephone number". Also, in the case where the user judges that a tag "TEL" does not express the telephone number, a change is made such that a tag "TEL" is not to be extracted in the important item "telephone number". Also, in the case where the important item "telephone number" becomes unnecessary, this important item "telephone number" is deleted. In the document important item extraction device of this first embodiment, the already extracted and stored important item will be maintained even when the setting for extracting this important item is deleted. Even if it is the important item that has become unnecessary at some point, the already stored item will be maintained so that it is possible to continue to use functions such as search function with respect to that item. Now the specific examples of the first embodiment will be described. (Embodiment 1-1) FIG. 1 shows an exemplary network system using the document important item extraction device according to this first embodiment. The exemplary system configuration shown in FIG. 1 comprises: (1) a WWW system formed by a WWW page creator 101, a WWW server 104, a proxy server 107 and a WWW page browser 113; (2) an e-mail system formed by an e-mail sender 102, a sender side e-mail server 105, a receiver side e-mail server 108 and an e-mail browser 114; (3) an e-news system formed by an e-news article sender 103, a sender side e-news server 106, a receiver side e-news server 109 and an e-news browser 115; and (4) a document important item extraction device 110 for automatically extracting important items from structured documents that are exchanged on the above systems. In the example of FIG. 1, a user carries out the desired operations by using a client 112 on which the WWW page browser 113, the e-mail browser 114 and the e-news browser 115 are operating. First, the operation related to the WWW system of FIG. 1 will be described with reference to FIG. 2. Usually, the WWW page on the WWW server 104 is created by the WWW page creator 101 and stored in the WWW server 104. At first, the user commands the display of the WWW page stored in the WWW server 104, with respect to the WWW page browser 111 which is an application on the client 112 (step S201). At this point, it is possible to directly specify the WWW server 104 in which the WWW page is stored, or specify a hyperlink contained in the WWW page that is already displayed on the WWW page browser 113. Upon receiving the command from the user, the WWW page browser 113 notifies the transmission request for the WWW page specified by the user to the proxy server 107 (r117 of FIG. 1, step S202). The proxy server 107 then similarly notifies the transmission request for the WWW page to the WWW server 104 (r118 of FIG. 1, step S203). The WWW server 104 then transmits the requested WWW page to the proxy server 107 (r119 of FIG. 1, step S204). The proxy server 107 inputs the received WWW page into the document important item extraction device 110 (r120 of FIG. 1, step S205). The document important item extraction device 110 analyzes the structure of the WWW page which is a structured document, and searches for the important items specified by the user therein (step S206). Then, whether any important item is found or not is judged (step S207). If the important item is found, the important item is extracted and stored into a recording device 111 (step S208), while a tag indicating that the important item has been extracted is added to the WWW page (step S209). Here, if no important item is contained in the WWW page, nothing is stored in the recording device 111. As the recording device 111, a hard disk device can be used, for example. After the extraction of the important items is finished, the document important item extraction device 110 outputs the WWW page to the proxy server 107 (r121 of FIG. 1). The proxy server 107 then transfers the WWW page to the WWW page browser 113 (r122 of FIG. 1, step S210). Upon receiving the WWW page, the WWW page browser 113 displays the WWW page (step S211). At this point, if the important items are contained in the WWW page, the tags indicating that they are extracted are attached by the document important item extraction device 110, so that their extracted regions are explicitly displayed by using the highlightened display, the reversed display, or the shaded display. Next, the operation related to the e-mail system will be described with reference to FIG. 3. The e-mail is transmitted to the sender side e-mail server 105 by the e-mail sender 102 (r123 of FIG. 1), and the sender side e-mail server 105 transmits the e-mail to the receiver side e-mail server 108 of the user who is the receiver of the e-mail (r124 of FIG. 1). The user then commands the display of the e-mail stored in the receiver side e-mail server 108, with respect to the e-mail browser 114 on the client 112 (step S301). Upon receiving the command from the user, the e-mail browser 114 notifies the transmission request for the e-mail to the receiver side e-mail server 108 (r125 of FIG. 1, step S302). The receiver side e-mail server 108 inputs the transmission requested e-mail into the document important item extraction device 110 (r126 of FIG. 1, step S303). The document important item extraction device 110 analyzes the structure of the e-mail which is a structured document, and searches for the important items specified by the user therein (step S304). Then, whether any important item is found or not is judged (step S305). If the important item is found, the important item is extracted and stored into the recording device 111 (step S306), while a tag indicating that the important item has been extracted is added to the e-mail (step S307). Here, if no important item is contained in the e-mail, nothing is stored in the recording device 111. After the extraction of the important items is finished, the document important item extraction device 110 outputs the e-mail to the receiver side e-mail server 108 (r127 of FIG. 1). The receiver side e-mail server 108 then transfers the e-mail to the e-mail browser 114 (r128 of FIG. 1, step S308). Upon receiving the e-mail, the e-mail browser 114 displays the e-mail (step S309). At this point, if the important items are contained in the e-mail, the tags indicating that they are extracted are attached by the document important item extraction device 110, so that their extracted regions are explicitly displayed by using the highlightened display, the reversed display, or the shaded display. Next, the operation related to the e-news system will be described with reference to FIG. 4. The e-news article is submitted to the sender side e-news server 106 by the e-news article sender 103 (r129 of FIG. 1), and the submitted e-news article is transferred from the sender side e-news server 106 to the receiver side e-news server 109 of the user (r130 of FIG. 1). The user then commands the display of the e-news article stored in the receiver side e-news server 109, with respect to the e-news browser 115 on the client 112 (step S401). Upon receiving the command from the user, the e-news browser 115 notifies the transmission request for the e-news article to the receiver side e-news server 109 (r131 of FIG. 1, step S402). The receiver side e-mail server 109 inputs the transmission requested e-news article into the document important item extraction device 110 (r132 of FIG. 1, step S403). The document important item extraction device 110 analyzes the structure of the e-news article which is a structured document, and searches for the important items specified by the user therein (step S404). Then, whether any important item is found or not is Judged (step S405). If the important item is found, the important item is extracted and stored into the recording device 111 (step S406), while a tag indicating that the important item has been extracted is added to the e-news article (step S407). Here, if no important item is contained in the e-news article, nothing is stored in the recording device 111. After the extraction of the important items is finished, the document important item extraction device 110 outputs the e-news article to the receiver side e-news server 109 (r133 of FIG. 1). The receiver side e-news server 109 then transfers the e-news article to the e-news browser 115 (r134 of FIG. 1, step S408). Upon receiving the e-news article, the e-news browser 115 displays the e-news article (step S409). At this point, if the important items are contained in the e-news article, the tags indicating that they are extracted are attached by the document important item extraction device 110, so that their extracted regions are explicitly displayed by using the highlightened display, the reversed display, or the shaded display. In the above described manner, the structured document is transmitted from a server to a client used by the user, and in a middle of its course, the document important item extraction device is operated to automatically extract and store the desired important items. Note that, in FIG. 1, the document important item extraction device 110 is shared by the proxy server 107, the receiver side e-mail server 108 and the receiver side e-news server 109, but it is also possible to provide a dedicated document important item extraction device 110 for each server separately. It is also possible to connect the document important item extraction device 110 to the client 112 in the case of a system which does not use the proxy server 107, the receiver side e-mail server 108 and the receiver side e-news server 109. Also, when a plurality of clients 112 are present, the document important item extraction device 110 may be shared among them, or a dedicated document important item extraction device 110 for each client 112 may be provided separately. Also, in FIG. 1, the document important item extraction device 110 is depicted as an independent device, but the document important item extraction device 110 may be implemented in each data relay server (each of the proxy server 107, the receiver side e-mail server 108 and the receiver side e-news server 109 in FIG. 1). In such a case, exchanges between the document important item extraction device 110 and the data relay server in the procedures of FIG. 2 to FIG. 4 become communications between the document important item extraction process and the data relay server process, for example. It is also possible to implement the document important item extraction device 110 in the data transmission and reception device (the client 112 in FIG. 1). In such a case, exchanges between the document important item extraction device 110 and the data relay server in the procedures of FIG. 2 to FIG. 4 will be replaced by communications between the document important item extraction process and the browser process, for example. Also, in this case, it is possible to utilize the data relay devices (the proxy server 107, the receiver side e-mail server 108 and the receiver side e-news server 109 of FIG. 1) as in FIG. 1, or not to utilize the data relay devices. Note that the above noted variations equally apply to the second and third embodiments to be described below. Next, a configuration and a method for setting up the "important item extraction method" will be described with references to FIG. 5 and FIG. 6. First, FIG. 5 shows an exemplary configuration of an extraction function portion of the document important item extraction device 110 and the data transmission and reception device (client device), for the purpose of setting up the important item extraction method. The document important item extraction device 110 has a synonym database 501, an extraction method database 502, and an important item database 503. The synonym database 501 stores synonyms of general terms that are set as the important items. For example, as the synonyms of "conference", words such as "discussion" and "meeting" are stored. The extraction method database 502 stores the "important item extraction method" set by the user, which will be referred to when the document important item extraction device 110 extracts the important items from the structured document. The important item database 503 stores the important items that are automatically extracted by the document important item extraction device 110, in a structured format which enables the subsequent search. The user sets up the important item extraction method by communicating with the document important item extraction device 110, using an important item extraction method setting application 506 in the client 112 which is the data transmission and reception device. For the extraction of the important items, a method using names of the tags that determine the structure of the structured document and a method for searching corresponding words from the full text of the structured document are available. The extraction can be carried out by using either one of these methods or both. The "important item extraction method" comprises "classifications" of the important items and their "extraction methods". it is possible to specify a plurality of important item classifications, and it is possible to specify a plurality of extraction methods with respect to one important item classification. Next, a procedure for setting up the "important item extraction method" will be described with reference to FIG. 6. The user sets up the important item extraction method by using the important item extraction method setting application 506. In the procedure of FIG. 6, first, the "classification" of the important items is specified (step S601). It is possible to give a name such as "meeting notice" to the classification, for example. Then, one or a plurality of the extraction methods are set up. The steps S602 to S608 constitute a loop processing for setting up the desired extraction method, which is to be executed as many times as the number of extraction methods to be set up. First, the extraction method is specified (step S602). In the case of carrying out the extraction by a method using names of the tags that determine the structure of the structured document, the extraction tag name in the structured document is specified (step S603). At this point, when the synonyms of the extraction tag name exist in the synonym database 501 (step S605), it is possible to specify a method which extracts all the synonyms as the extraction tag name (step S606). When the use of the synonyms is specified, the search using all the synonyms as the extraction tag name is carried out at a time of extracting the important items in the structured document at the document important item extraction device 110 (step S607). In the case of carrying out the extraction by a method for searching a corresponding word from the full text of the structured document, the extraction word is specified (step S604). At this point, when the synonyms of the extraction word exist in the synonym database 501 (step S605), it is possible to specify all the synonyms as the extraction word to be searched (step S606). When the use of the synonyms is specified, the search using all the synonyms as the extraction word is carried out at a time of extracting the important items in the structured document at the document important item extraction device 110 (step S607). Also, at a time of specifying the extraction tag name of the structured document, if the DTD referred by the structured document is specified, types of the tag names that can be contained in the structured document can be determined from the DTD, so that it is preferable to be able to specify only those tags which are potentially contained in the structured document as the extraction tag name. In this way, it is possible to prevent an error in the setting of the important item tag name. It is also possible to specify the other extraction method repeatedly (step S608). When the classification of the important items and one or a plurality of the extraction methods for that classification are set up as in the above, the important item extraction method setting application 506 notifies this setting to the document important item extraction device 110 (step S609). The document important item extraction device 110 then stores this setting in the extraction method database 502 (step S610). It is also possible to set up a plurality of classifications by repeating the step S601 and the subsequent steps. Next, a procedure for extracting the important items at the document important item extraction device 110 will be described with references to FIG. 5 and FIG. 7. FIG. 7 shows the important item extraction procedure of the document important item extraction device 110. Note that the following description of the extraction procedure also utilizes exemplary structured documents shown in FIGS. 8A and 8B, exemplary states of the structured document in a middle of the extraction processing as shown in FIGS. 9A and 9B, exemplary settings of the extraction method as shown in FIGS. 10A and 10B, an exemplary synonym database shown in FIG. 11, and exemplary extraction results shown in FIGS. 12A and 12B. Among them, FIGS. 8A, 9A, 10A and 12A correspond to one example, while FIGS. 8B, 9B, 10B and 12B correspond to another example. Since the WWW page, e-mail, and e-news article are in forms of text files, the text files or a memory storing the text will be used for the input to the document important item extraction device 110. The input text is usually structured by tags as in a structured document 801 shown in FIG. 8A or a structured document 802 shown in FIG. 8B. Consequently, the document structure is analyzed by using tags, as in a document structure 901 shown in FIG. 9A or a document structure 902 shown in FIG. 9B (step S701). Then, the document important item extraction device 110 reads out the important item extraction method set by the user such as an important item extraction method 1001 shown in FIG. 10A or an important item extraction method 1002 shown in FIG. 10B, from the extraction method database 502 (step S702), and the extraction of the important items is carried out. At this point, when a plurality of important item extraction methods are specified as in the important item extraction method 1002, the extraction is carried out repeatedly for all the important item extraction methods (step S716). Then, whether a method using names of the tags of the structured document is specified as the extraction method or not is judged (step S703). When the method using names of the tags that determine the structure of the structured document is specified as the extraction method as in the important item extraction method 1001, the extraction tag name is searched in the analyzed document structure (step S704). In this example, the extraction tag name <meeting> which is specified in the extraction method is contained in the document structure 901 (step S706) so that the extraction tag <meeting> and its lower layer structure 1201 are extracted as the important items, and stored into the important item database 503 (step S714). When the method for searching a corresponding word from the full text of the structured document is specified as the extraction method as in the important item extraction method 1002, the extraction word is searched in the analyzed document structure (step S705). In this example, the extraction word "price" which is specified in the extraction method is not contained in the document structure 902, so that nothing is stored into important item database 503 (step S707). However, in this example, the use of synonyms is specified in the extraction method (step S709) so that the search using the synonyms is carried out (step S711). By referring to the synonym database 1101 shown in FIG. 11, the document structure 902 contains a synonym "special offer" among the synonyms 1101 of the specified extraction word, so that a tag <comment> that contains the "special offer" that is the extraction word and its lower layer structure 1202 are extracted as the important items, and stored into the important item database 503 (step S715). The above processing is repeatedly executed until the searches for all the important items are finished (step S717). Next, a procedure for storing the important items in the document important item extraction device 110 will be described with references to FIG. 5, FIG. 10, FIG. 13 and FIG. 14. For the important item database 503 into which the important items are stored by the document important item extraction device 110, a database capable of storing structured data is used. For example, the object-oriented database can be used. FIG. 13 shows an exemplary internal structure of the important item database 503. Note that the content shown in FIG. 13 corresponds to the extraction result in the case of extracting the important items for the classification "meeting" and the classification "price" in the extraction method settings shown in FIGS. 10A and 10B, from the two structured documents shown in FIGS. 8A and 8B, and also extracting the important items using a tag name =<goods> for the classification "goods". In the important item database 1315, the classifications of the important items, i.e., "meeting" 1302, "goods" 1308, and "price" 1311, that are used at a time of setting the important item extraction method are stored in advance. The important items that are extracted by the document important item extraction device 110 using the important item extraction method stored in the extraction method database 502 can be stored effectively under the "classification" of the important item extraction method used in the extraction. By storing in this way, it becomes possible to distinguish the extracted important items according to the respective important item extraction methods. For example, the important items extracted by the extraction method 1001 shown in FIG. 10A are stored under the classification "meeting" 1302. It is also preferable to attach links for relating the important items to each other, for the important items that are extracted from the identical structured document. For example, when the important item 1309 which is classified into the classification "goods" 1308 and the important item 1312 which is classified into the classification "price" 1311 are extracted from the identical structured document, the important item 1309 and the important item 1312 can be related by a link 1314. By relating the important items by links in this way, it is possible to preserve the relationship among the important items that are stored by the different important item extraction methods from the same structured document, so that the relationship that a plurality of the important items are contained in the same structured document can be utilized at a time of searching the important item. FIG. 14 shows another exemplary internal structure of the important item database 503. An example of FIG. 14 is directed to the case where the extracted important items are added further to the example of FIG. 13. This example of FIG. 14 shows that the important item 1325 that is related to the classification "meeting" 1302 is extracted from the other structured document and this important item 1325 is added under the classification "meeting" 1302. It also shows the important item 1320 that is related to the classification "goods" 1308 and the important item 1322 that is related to the classification "price" 1311 are extracted from the other structured document, and respectively added under the classification "meeting" 1302 and the classification "price" 1311. It also shows that the important item 1320 that is classified into the classification "goods" 1308 and the important item 1322 that is classified into the classification "price" 1311 are extracted from the identical structured document so that the important item 1320 and the important item 1322 are related by a link 1324. (Embodiment 1-2) Next, a method for displaying the structured document and a method for specifying, adding, changing, or deleting the important item extraction method at the browser (the WWW page browser 113, the e-mail browser 114 and the e-news browser 115 of FIG. 1) in the data transmission and reception device (the client 112 of FIG. 1) will be described. Here, the operations are the same for the WWW page browser 113, the e-mail browser 114, and the e-news browser 115, so that the operations on the WWW page browser 113 will be described as an example. First, an exemplary operation for newly specifying the important item will be described with references to FIG. 15, FIG. 16 and FIG. 17. FIG. 15 shows an exemplary display of the structured document that contains no important item at the WWW page server 113. In FIG. 15, none of a title 1601 of the structured document, a content 1602 of the structured document, and a note section 1603 of the structured document contains the important item, so that the structured document is displayed in its original state of creation. At this point, suppose that the note section 1603 of the structured document is to be newly specified as the important item on the WWW page browser 113. The user specifies a region of the note section 1603 of the structured document by using a mouse pointer 1604 which is the position specifying device, and presses an important item specify button 1605, for example. FIG. 16 shows a situation where a region of the note section 1603 is specified. When the region is specified and the important item specify button 1605 is pressed, the WWW page browser 113 displays an important item specifying screen as shown in FIG. 17, and sets up an extraction name input portion 1802 by searching a tag of the portion at the region specified by user from the structured document. The user then enters the important item name into an important item name input portion 1801. Similarly, the user presses a tag extraction specify button 1803 in the case of using a tag name as the extraction method, or a word extraction specify button 1804 in the case of using a word as the extraction method. Also, the user presses a full text store specify button 1805 in the case of storing the entire structured document containing the important item, or a tag store specify button 1806 in the case of storing only tags which are the important items. Finally, the user presses an input content decide button 1807 so as to decide on the input content and specify the extraction of the important item to the document important item extraction device 110. Next, with reference to FIG. 16 and FIG. 17, an exemplary operation for adding the note section 1603 of the structured document to the existing important items will be described. Starting from a display state of FIG. 15, the user specifies a region of the note section 1603 of the structured document by using the mouse pointer 1604 which is the position specifying device as shown in FIG. 16, for example, and presses an important item add button 1606. When the region is specified and the important item add button 1606 is pressed, the WWW page browser 113 displays an important item adding screen as shown in FIG. 17, and sets up the extraction name input portion 1802 by searching a tag of the portion at the region specified by user from the structured document. The user then enters the important item name into an important item name input portion 1801. Similarly, the user presses the tag extraction specify button 1803 in the case of using a tag name as the extraction method, or the word extraction specify button 1804 in the case of using a word as the extraction method. Also, the user presses the full text store specify button 1805 in the case of storing the entire structured document containing the important item, or the tag store specify button 1806 in the case of storing only tags which are the important items. Finally, the user presses the input content decide button 1807 so as to decide on the input content and specify the addition of the important item to the document important item extraction device 110. Next, with reference to FIG. 16 and FIG. 17, an exemplary operation for changing the important item when the note section 1603 of the structured document is the existing important item will be described. Starting from a display state of FIG. 15, the user specifies a region of the note section 1603 of the structured document by using the mouse pointer 1604 which is the position specifying device as shown in FIG. 16, for example, and presses an important item change button 1607. When the region is specified and the important item change button 1607 is pressed, the WWW page browser 113 displays an important item changing screen as shown in FIG. 17, and sets up the corresponding important item name into the important item name input portion 1801, and sets up the extraction name into the extraction name input portion 1802 similarly. Also, the user presses the tag extraction specify button 1803 in the case of using a tag name as the extraction method, or the word extraction specify button 1804 in the case of using a word as the extraction method. Also, the user presses the full text store specify button 1805 in the case of storing the entire structured document containing the important item, or the tag store specify button 1806 in the case of storing only tags which are the important items. The user then changes the setting content of that important item, presses the input content decide button 1807 so as to decide on the input content and specify the change of the important item extraction method to the document important item extraction device 110. Next, with reference to FIG. 16 and FIG. 17, an exemplary operation for deleting the important item when the note section 1603 of the structured document is the existing important item will be described. Starting from a display state of FIG. 15, the user specifies a region of the note section 1603 of the structured document by using the mouse pointer 1604 which is the position specifying device as shown in FIG. 16, for example, and presses an important item delete button 1608. When the region is specified and the important item change button 1608 is pressed, the WWW page browser 113 displays an important item deleting screen as shown in FIG. 17, and sets up the corresponding important item name into the important item name input portion 1801, and sets up the extraction name into the extraction name input portion 1802 similarly. Also, the user presses the tag extraction specify button 1803 in the case of using a tag name as the extraction method, or the word extraction specify button 1804 in the case of using a word as the extraction method. Also, the user presses the full text store specify button 1805 in the case of storing the entire structured document containing the important item, or the tag store specify button 1806 in the case of storing only tags which are the important items. In the case of carrying out the deletion, after confirming the setting content of that important item, the user presses the input content decide button 1807 so as to specify the deletion of the important item to the document important item extraction device 110. According to this first embodiment, when the document important item extraction device is used at a time of viewing the structured document that is delivered from the structured document delivery device such as WWW server, the document important item extraction device automatically extracts those items which are important for the user from the received structured document and store them in a memory device, on behalf of the user. The operation to extract and store the important items from the structured document is carried out automatically by the document important item extraction device, so that the user can be relieved from the tedious task of extracting and storing the important items from each received structured document by himself/herself, and it is possible to eliminate a situation where the extracting and storing operation is forgotten. Also, when the document important item extraction device of this first embodiment is used at a time of viewing the structured document that is delivered from the structured document delivery device such as WWW server, the extracted important items can be checked at the data transmission reception device such as browser that is used by the user, so that it becomes possible to check if the extraction and storing of the important items has been carried out as intended by the user or not. Also, by using the important item extraction method setting application at the data transmission and reception device, it is possible to specify, add, change, or delete the important items to be extracted, so that it becomes possible for the user to automatically extract appropriate important items according to the need. Second Embodiment Referring now to FIG. 18 to FIG. 22, the second embodiment of the database construction scheme according to the present invention will be described in detail. In the first embodiment described above, the basic function of the document important item extraction device, that is, the function for extracting and storing important items from structured documents, has been described. In this second embodiment, in addition to the function for storing the important items extracted from the structured documents, a function for newly generating attaching items related to the extracted important items and storing the extracted important items and the generated attaching items are stored either in correspondence to each other or as a set. As the attaching items related to the important items, various information can be generated. For instance, by generating and storing the data at which the important item is extracted from the structured document, it becomes possible to ascertain how fresh that information is later on. Also, in this second embodiment, a retrieval function that can be provided in the document important item extraction device will be described. When the retrieval function is provided, it becomes possible for the user to efficiently search out the necessary information from the stored important items and attaching items. Note that the retrieval function will be described as the second embodiment here, but it is also possible to provide the retrieval function (for retrieving the important items) in the document important item extraction device of the first embodiment. As described in the first embodiment, the document important item extraction device can be realized either by a data transmission and reception device (client 112 of FIG. 1) for transmitting and receiving structured documents, or by a data relay device (proxy server 107, receiver side e-mail server 108 and receiver side e-news server 109 of FIG. 1) for transmitting and receiving structured documents. Moreover, instead of the latter, it is also possible to provide the document important item extraction device as an independent device external to the data relay device and carry out information exchanges between the data relay device and the document important item extraction device, and furthermore the document important item extraction device that is provided as an independent device external to the data relay device can be shared among a plurality of data relay devices. Now, the document important item extraction device has the basic function of receiving structured documents delivered via a communication path from the structured document delivery device (WWW server 104, sender side e-mail server 105 and sender side e-news server 106 of FIG. 1), and automatically extracting important items from the received structured documents and storing them into a recording device. Conditions to be satisfied by those items that are important for the user of the document important item extraction device among items contained in the structured documents are commanded to the document important item extraction device by the user. Once the command from the user is made, thereafter the document important item extraction device carries out the extraction of the important items from the structured documents and the storing into the recording device according to the command content. A method for specifying the conditions to be satisfied by the important items in the structured documents to the document important item extraction device can be any of the following, for example:
An information summarizing the conditions to be satisfied by those items that are important to the user among items contained in the structured document is stored in the memory device within the document important item extraction device in a table form, and this table can be referred by reading it out from the memory device whenever necessary. Hereafter this table will be referred to as "structured document important item condition table". In the case where the important item in the structured document is specified by a tag name as in the above method (1), the document important item extraction device extracts the item that has the specified tag name from the structured document and stores it in the recording device. In the case where the important item in the structured document is specified by a tag attribute name as in the above method (2), the document important item extraction device extracts the item that has the specified tag attribute name from the structured document and stores it in the recording device. In the case where the important item in the structured document is specified by a tag attribute value as in the above method (3), the document important item extraction device extracts the item that has the specified tag attribute value from the structured document and stores it in the recording device. In the case where the important item in the structured document is specified by a keyword contained in text other than tags as in the above method (4), the document important item extraction device extracts the item that contains the specified keyword from the structured document and stores it in the recording device. Now, the document important item extraction device having the function for generating and storing attaching items receives the structured document delivered via a communication path from the structured document delivery device, automatically extracts the important items from the received structured document, automatically generates attaching items related to the extracted important items, and stores both of them either in correspondence to each other or in set. Conditions to be satisfied by attaching items to be generated are commanded to the document important item extraction device by the user (using an attaching item command function). Once the command from the user is made, thereafter the document important item extraction device carries out the generation of attaching items from the structured document and storing into the recording device according to the command content. A method for specifying the attaching item related to the extracted important item in the structured document from the user to the document important item extraction device can be any of the following, for example:
An information summarizing the conditions to be satisfied by the attaching items related to the important items in the structured document is stored in the memory device within the document important item extraction device in a table form, and this table can be referred by reading it out from the memory device whenever necessary. Hereafter this table will be referred to as "structured document important item related attaching item condition table". In the case where the attaching item related to the important item in the structured document is specified as date and time at which the structured document is extracted as in the above method (1), the document important item extraction device generates the date and time as data in a format of an item to be stored in the recording device, that is, in a data format using a tag, and store that data into the recording device. In the case where the attaching item related to the important item in the structured document is specified as a location at which the structured document exists as in the above method (2), the document important item extraction device checks which structured document of which structured document delivery device is the target structured document, generates data in a format of an item to be stored in the recording device, that is, in a data format using a tag, and store that data into the recording device. In the case where the attaching item related to the important item in the structured document is specified as locations at which items other than the extracted important items exist as in the above method (3), the document important item extraction device checks which items of which structured document of which structured document delivery device are the target structured document items, generates data in a format of an item to be stored in the recording device, that is, in a data format using a tag, and store that data into the recording device. Now, the document important item extraction device having the retrieval function is capable of carrying out the retrieval of the important items stored in the recording device (in the case of not having the function for generating and storing the attaching items) or the retrieval of the important items and the attaching items (in the case of having the function for generating and storing the attaching items). When the user specifies conditions to be satisfied by the important items to be retrieved to the document important item extraction device, the document important item extraction device retrieves those important items which match the retrieval conditions from all the important items already stored in the recording device. If the matching important item is found, that important item is displayed, whereas if the matching important item is not found, the fact that it is not found is displayed. The items stored in the recording device of the document important item extraction device include the following two types.
The retrieval target items include both of the above two types of items. A method for specifying an item to be retrieved from the user to the document important item extraction device can be any of the following:
In the case where the desired retrieval target item of the user is specified by a tag name as in the above method (1), the item that has the specified tag name among the items stored in the recording device is searched and read out. In the case where the desired retrieval target item of the user is specified by a tag attribute name as in the above method (2), the item that has the specified tag attribute name among the items stored in the recording device is searched and read out. In the case where the desired retrieval target item of the user is specified by a tag attribute value as in the above method (3), the item that has the specified tag attribute value among the items stored in the recording device is searched and read out. In the case where the desired retrieval target item of the user is specified by a keyword contained in text other than tags as in the above method (4), the item that contains the specified keyword among the items stored in the recording device is searched and read out. Next, the data format used at a time of storing the important items and the attaching items into the recording device will be described. FIG. 18 shows an exemplary important item and attaching item database which stores the important items and the attaching items. In this example, the meeting date enclosed by the <date> tags and the meeting place enclosed by <place> tags are extracted from the structured document as the important items. Also, a URL indicating a location where this structured document was originally located and a date on which the important items are extracted are generated as the attaching items related to the extracted important items, and respectively enclosed by <URL> tags and <extractday> tags. The extracted important items are enclosed by <main> tags, while the generated attaching items are enclosed by <sub> tags so that they constitute a single structured document as a whole. At a time of carrying out the retrieval, any of the following three retrieval methods can be used appropriately.
In the following, the configuration and the operation of the document important item extraction device of this second embodiment will be described in further detail. FIG. 19 shows an exemplary configuration of the structured document storage and retrieval system containing the document important item extraction device of this second embodiment which has the function for extracting and storing the important items, the function for generating and storing the attaching items, and the retrieval function. In this exemplary configuration, the document important item extraction device is realized as the data relay device. As shown in FIG. 19, this structured document storage and retrieval system comprises a document important item extraction device 220, a structured document viewing device 210, a communication path 270, and a structured document transmission and reception device 280. The document important item extraction device 220 further comprises a structured document viewing device request analysis unit 221, a structured document reception unit 222, a structured document important item extraction unit 223, a structured document important item related attaching item generation unit 224, a structured document important item command control unit 225, a structured document important item related attaching item command control unit 226, a retrieval command control unit 227, a memory control unit 228, and a memory unit 229. [Structured Document Viewing Device 210] The structured document viewing device 210 comprises a structured document viewing unit 230; an important item command unit 240, an attaching item command unit 250, and a retrieval command unit 260. The structured document viewing unit 230 has a structured document request input unit 231 and a structured document display unit 232. The important item command unit 240 has an important item command input unit 241 and an important item command execution result display unit 242. The attaching item command unit 250 has an attaching item command input unit 251 and an attaching item command execution result display unit 252. The retrieval command unit 260 has a retrieval command input unit 261 and a retrieval result display unit 262. <Structured Document Viewing Unit 230> The structured document viewing unit 230 receives a structured document viewing request from the user and transmits a structured document delivery request to the structured document transmission and reception device 280, or receives and displays the structured document transmitted from the structured document transmission and reception device 280. The structured document request input unit 231 is a unit where the user enters the structured document viewing request. A method by which the user makes the structured document viewing request can be a method for specifying a URL. The structured document display unit 232 is a unit for displaying the structured document transmitted from the structured document transmission and reception device 280 to the structured document viewing unit 230. <Important Item Command Unit 240> The important item command unit 240 is a unit for specifying conditions to be satisfied by items that are important to the user of the document important item extraction device 220 among the items contained in the structured document received by the document important item extraction device 220, from the user to the document important item extraction device 220. The user enters conditions to be satisfied by items that are important to the user among the items contained in the structured document received by the document important item extraction device 220, at the important item command input unit 241. The important item command execution result display unit 242 displays data transmitted from the structured document transmission and reception device 280 to the important item command unit 240. <Attaching Item Command Unit 250> The attaching item command unit 250 is a unit for specifying conditions to be satisfied by attaching items related to the important items extracted from the structured document by the document important item extraction device 220, from the user to the document important item extraction device 220. The user enters conditions to be satisfied by attaching items related to the important items extracted from the structured document by the document important item extraction device 220, at the attaching item command input unit 251. The attaching item command execution result display unit 252 displays data transmitted from the structured document transmission and reception device 280 to the attaching item command unit 250. <Retrieval Command Unit 260> The retrieval command unit 260 is a unit for specifying conditions to be satisfied by a desired retrieval target item of the user, from the user to the document important item extraction device 220. The user enters conditions to be satisfied by the own desired retrieval target item among the items stored in the document important item extraction device 220, at the retrieval command input unit 261. The retrieval result display unit 262 displays data transmitted from the structured document transmission and reception device 280 to the retrieval command unit 260. The communication path 270 relays the structured document delivery request transmitted from the structured document viewing unit 230 with respect to the document important item extraction device 220, and transmits it to the structured document delivery device such as WWW server or e-mail server. The communication path 270 also relays the structured document transmitted from the structured document delivery device such as WWW server or e-mail server, and transmits it to the document important item extraction device 220. [Structured Document Transmission and Reception Device 280] The structured document transmission and reception device 280 is located in a middle of the document important item extraction device 220 and the structured document viewing device 210, and relates data transmitted and received between the document important item extraction device 220 and the structured document viewing device 210. [Document Important Item Extraction Device 220] The document important item extraction device 220 receives the structured document transmitted from the structured document delivery device such as WWW server or e-mail server and transfers the received structured document to the structured document viewing device 210 through the structured document transmission and reception device 280, while extracting the important items from the received structured document, generating the attaching items related to the extracted important items, and storing them in set into the memory unit 229. In the case where the structured document with the same document title has been received before, there is a need to check whether there is a need to carry out the extraction and the generation again or not. Also, the document important item extraction device 220 carries out the addition, change, or deletion of the important items and the attaching items according to a method specified by the user using the important item command unit 240 and the attaching item command unit 250. In addition, when the user notifies the desired retrieval target item to the document important item extraction device 220 by using the retrieval command unit 260, the document important item extraction device 220 searches and reads out the item matching the user's request among the items stored in the memory unit 229, and transfers it to the retrieval command unit 260 through the structured document transmission and reception device 280. <<Structured Document Viewing Device Request Analysis Unit 221>> The structured document viewing device request analysis unit 221 receives a content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 through the structured document transmission and reception device 280, analyzes the received content, and transfers it to appropriate place. Specifically, the content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 can be any of the following four. (1) A structured document delivery request transmitted from the structured document viewing unit 230. (2) An important item command transmitted from the important item command unit 240. (3) An attaching item command transmitted from the attaching item command unit 250. (4) A retrieval command transmitted from the retrieval command unit 260. In the case where the content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 is the structured document delivery request transmitted from the structured document viewing unit 230, the structured document delivery device on which the requested structured document is located is analyzed, and the structured document delivery request is transmitted via the communication path 270, either to the structured document delivery device such as WWW server or e-mail server on which the requested structured document exists, or to the structured document transmission and reception device located between the structured document delivery device on which the requested structured document exists and the document important item extraction device 220. In the case where the content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 is the important item command transmitted from the important item command unit 240, it is transferred to the structured document important item command control unit 225. In the case where the content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 is the attaching item command transmitted from the attaching item command unit 250, it is transferred to the structured document important item related attaching item command control unit 226. In the case where the content transmitted from the structured document viewing unit 230 to the document important item extraction device 220 is the retrieval command transmitted from the retrieval command unit 260, it is transferred to the retrieval command control unit 227. <<Structured Document Reception unit 222>> The structured document reception unit 222 receives the structured document transmitted from the structured document delivery device such as WWW server or e-mail server to the document important item extraction device 220 via the communication path 270, and makes two copies of the received structured document. One of the copied structured document is transferred to the structured document viewing device 210 through the structured document transmission and reception device 280, while the other one of the copied structured document is transferred to the structured document important item extraction unit 223. <<Structured Document Important Item Extraction Unit 223>> The structured document important item extraction unit 223 receives the structured document transmitted from the structured document reception unit 222, and carries out the extraction of the important items from the structured document according to the content of the structured document important item condition table. In the case where the received structured document has the same document title as the previously received structured document, whether there is a need to carry out the extraction of the important items again or not is checked. When it is judged that there is a need to carry out the extraction of the important items again as a result of this check, the structured document important item extraction unit 223 extracts all the items that are important to the user from the structured document according to the latest content of the structured document important item condition table. When the extraction operation is finished, the structured document important item extraction unit 223 transmits the structured document in a state before the extraction is carried out and all the extracted important items to the structured document important item related attaching item generation unit 224. <<Structured Document Important Item Related Attaching Item Generation Unit 224>> The structured document important item related attaching item generation unit 224 receives the structured document and the important items extracted from the structured document which are transmitted from the structured document important item extraction unit 223, and carries out the generation of the attaching items according to the content of the structured document important item related attaching item condition table. In the case where the received structured document has the same document title as the previously received structured document, whether there is a need to carry out the generation of the attaching items again or not is checked. When it is judged that there is a need to carry out the generation of the attaching items again as a result of this check, the structured document important item related attaching item generation unit 224 generates the attaching items related to the important items extracted by the structured document important item extraction unit 223 according to the latest content of the structured document important item related attaching item condition table. When the generation operation is finished, the structured document important item related attaching item generation unit 224 transmits the structured document important items extracted by the structured document important item extraction unit 223 and the structured document important item related attaching items generated by the structured document important item related attaching item generation unit 224 together to the memory control unit 228, and commands the memory control unit 228 to store these extracted and generated items into the memory unit 229. <<Structured Document Important Item Command Control Unit 225>> The structured document important item command control unit 225 receives the command content transmitted from the structured document viewing device request analysis unit 221, and carries out the operation on the structured document important item condition table according to the received content. <<Structured Document Important Item Related Attaching Item Command Control Unit 226>> The structured document important item related attaching item command control unit 226 receives the command content transmitted from the structured document viewing device request analysis unit 221, and carries out the operation on the structured document important item related attaching item condition table according to the received content. <<Retrieval Command Control Unit 227>> The retrieval command control unit 227 receives the command content transmitted from the structured document viewing device request analysis unit 221, and analyzes the retrieval condition. The retrieval command control unit 227 then commands the memory control unit 228 to read out the item matching the retrieval condition from the memory unit 229, and transmits the information transmitted from the memory control unit 228 in response to the command, to the retrieval command unit 260 through the structured document transmission and reception device 280. <<Memory Control Unit 228>> The memory control unit 228 receives a request for reading out and transferring data from the memory unit 229 or a request for writing data into the memory unit 229 which is transmitted from the structured document important item related attaching item generation unit 224, the structured document important item command control unit 225, the structured document important item related attaching item command control unit 226, or the retrieval command control unit 227, and executes that request. <<Memory Unit 229>> The memory unit 229 carries out the data storing. Specifically, data to be stored here include the following. (1) The important items extracted from the structured documents. (2) The attaching items related to the important items extracted from the structured documents. (3) The structured document important item condition table. (4) The structured document important item related attaching item condition table. Next, the operation to be carried out in the case where it is desired to add a condition to be satisfied by the attaching items related to the important items extracted from the structured document newly to the structured document important item related attaching item condition table will be described. FIG. 20 shows an exemplary procedure for this operation. The user enters a condition to be satisfied by the attaching items related to the important items extracted from the structured document and the fact that it is desired to add this condition newly to the structured document important item related attaching item condition table, at the attaching item command input unit 251 of the attaching item command unit 250. The entered command content is transferred from the attaching item command unit 250 to the document important item extraction device 220 through the structured document transmission and reception device 280 (step S1601). The structured document viewing device request analysis unit 221 of the document important item extraction device 220 receives the command content transmitted from the attaching item command unit 250. The structured document viewing device request analysis unit 221 then analyzes the received command content, and transfers it to the structured document important item related attaching item command control unit 226 (step S1602). The structured document important item related attaching item command control unit 226 receives the command content transferred from the structured document viewing device request analysis unit 221, analyzes the command content, and learns that the command content is an addition of a new condition to the structured document important item related attaching item condition table (step S1603). The attaching item command unit 250 then commands the addition of a new condition to the structured document important item related attaching item condition table, with respect to the memory control unit 228 (step S1604). The memory control unit 228 carries out the addition of the new condition to the structured document important item related attaching item condition table. Then, an indication of a success/failure is transmitted to the structured document important item related attaching item command control unit 226 when the addition is successful/failure (steps S1605, S1606, S1607). The structured document important item related attaching item command control unit 226 transfers the content received from the memory control unit 228 to the structured document viewing device request analysis unit 221 (step S1608). The structured document viewing device request analysis unit 221 transmits the content received from the structured document important item related attaching item command control unit 226 to the attaching item command unit 250 through the structured document transmission and reception unit 280 (step S1609). The attaching item command unit 250 receives the content transmitted from the structured document viewing device request analysis unit 221, and displays it at the attaching item command execution result display unit 252 (step S1610). Here, the description of the change or the deletion of the condition in the structured document important item related attaching item condition table and the display of the structured document important item related attaching item condition table will be omitted. Next, the operation carried out since the user issues the structured document viewing request until the important items and the attaching items are stored into the structured document important item device 220 will be described. FIG. 21 shows an exemplary procedure for this operation. The user of the structured document viewing unit 230 enters a viewing request for a structured document that he/she wishes to view to the structured document request input unit 231. The structured document viewing unit 230 receives the user inputs, and transmit the structured document delivery request to the document important item extraction device 220 (step S1701). The structured document viewing device request analysis unit 221 of the document important item extraction device 220 receives the structured document delivery request transmitted from the structured document viewing unit 230, analyzes the structured document delivery device on which the requested structured document exists, and transmits the structured document delivery request via the communication path 270, either to the structured document delivery device such as WWW server or e-mail server on which the requested structured document exists, or to the structured document transmission and reception device located between the structured document delivery device on which the requested structured document exists and the document important item extraction device 220 (step S1702). The structured document delivery device that received the structured document delivery request then transmits the requested structured document to the document important item extraction device 220 via the communication path 270 (step 1703). The structured document reception unit 222 of the document important item extraction device 220 receives the structured document transmitted from the structured document delivery device such as WWW server or e-mail server via the communication path 270 to the document important item extraction device 220, and makes copies of the received structured document. One copy of the structured document is transferred to the structured document viewing device 210 through the structured document transmission and reception device 280 while the other copy is transmitted to the structured document important item extraction unit 223 (step S1704). The structured document viewing unit 230 receives the structured document transmitted from the document important item extraction device 220 through the structured document transmission and reception device 280, and displays it at the structured document display unit 232. Also, the structured document important item extraction unit 223 receives the structured document transmitted from the structured document reception unit 222 (step S1705). Next, the latest structured document important item condition table is prepared in the structured document important item extraction unit 223, and whether there is a need to carry out the extraction of the important items from the received structured document or not is checked (step S1707). When there is a need to carry out the extraction of the important items, all the important items are extracted from the structured document according to the latest content of the structured document important item condition table. When the extraction operation is finished, the structured document in a state before the extraction and all the extracted important items are transmitted to the structured document important item related attaching item generation unit 224 (step S1708). The structured document important item related attaching item generation unit 224 receives the structured document and all the extracted important items which are transmitted from the structured document important item extraction unit 223. Then, the latest structured document important item related attaching item condition table is prepared in the structured document important item related attaching item generation unit 224, and whether there is a need to carry out the generation of the attaching items or not is checked (step S1709). When there is a need to carry out the generation of the attaching items, all the attaching items related to the important items are generated according to the latest content of the structured document important item related attaching item condition table (step S1710). When the generation operation is finished, the structured document important item related attaching item generation unit 224 transmits the structured document important items extracted by the structured document important item extraction unit 223 and the structured document important item related attaching items generated by the structured document important item related attaching item generation unit 224 together, to the memory control unit 228, and command the storing of these items into the memory unit 229 with respect to the memory control unit 228 (step S1711). The memory control unit 228 receives the structured document important items extracted by the structured document important item extraction unit 223 and the structured document important item related attaching items generated by the structured document important item related attaching item generation unit 224, and stores the received items into the memory unit 229 (step S1712). Next, the operation to be carried out in the case where the user wishes to retrieve the items stored in the document important item extraction device 220 will be described. FIG. 22 shows an exemplary procedure for this operation. The user enters the conditions to be satisfied by the items he/she wishes to retrieve among the items stored in the document important item extraction device 220 into the retrieval command input unit 261 of the retrieval command unit 260. The retrieval command unit 260 transmits the content entered by the user to the document important item extraction device 220 through the structured document transmission and reception device 280 (step S1801). The structured document viewing device request analysis unit 221 of the document important item extraction device 220 receives the command content transmitted from the retrieval command unit 260, analyzes the received command content, and transfers it to the retrieval command control unit 227 (step S1802). The retrieval command control unit 227 receives the command content transferred from the structured document viewing device request analysis unit 221, and analyzes the received command content to obtain the retrieval condition (step S1803). Then, the retrieval command control unit 227 judges whether any item matching the retrieval condition is stored or not (step S1804). When the item matching the retrieval condition is stored, the reading of this item from the memory unit 229 is commanded to the memory control unit 228. The memory control unit 228 then reads out the item whose reading is commanded from the retrieval command control unit 227, from the memory unit 229. and transmits it to the retrieval command control unit 227 (step S1805). When the item matching the retrieval condition does not exist, this fact is notified to the retrieval command control unit 227 (step S1806). The retrieval command control unit 227 transfers the content received from the memory control unit 228 to the structured document viewing device request analysis unit 221 (step S1807). The structured document viewing device request analysis unit 221 transmits the content received from the retrieval command control unit 227 to the retrieval command unit 260 through the structured document transmission and reception device 280 (step S1808). The retrieval command unit 260 receives the transmitted content and displays it at the retrieval result display unit 262 (step S1809). According to this second embodiment, when the document important item extraction device is used at a time of viewing the structured document that is delivered from the structured document delivery device such as WWW server, the document important item extraction device automatically extracts those items which are important for the user from the received structured document, generates the attaching items related to the extracted items (date and time at which the important items of the structured document are extracted, a location at which the structured document exists, locations at which items other than the important items of the structured document exist, etc.) and stores both of them as a set in a memory device, on behalf of the user. The operation to extract, generate and store these items is carried out automatically by the document important item extraction device, so that the user can be relieved from the tedious task of extracting and storing the important items from each received structured document by himself/herself, and it is possible to eliminate a situation where the extracting and storing operation is forgotten. Also, by retrieving the important items of the structured document by the method described above at the document important item extraction device, it becomes possible to obtain the desired information from the important items of the structured document and the attaching items related to the important items of the structured document which are stored in advance. At a time of specifying items that are important for the user to the document important item extraction device, when the items that are important for the user cannot be extracted from the structured document because the items are specified inappropriately, if the location at which the structured document exists is maintained as the attaching item related to the important items of the structured document, it becomes possible to obtain the desired information by requesting the transfer of the entire structured document again to the structured document delivery device. Third Embodiment Referring now to FIG. 23 to FIG. 38, the third embodiment of the database construction scheme according to the present invention will be described in detail. In this third embodiment, at a time of storing the important items extracted at the document important item extraction device, the important items are stored separately for the user who extracted these important items. In this way, it becomes easier to take out the important items at a time of reading or retrieving the important items set by the user later on. Such a document important item extraction device will be described in the embodiments 3-1 and 3-2 described below. The embodiment 3-1 is directed to the case of realizing the document important item extraction device on a data transmission and reception device (a configuration in which it is operated on the client utilized by the user), and the embodiment 3-2 is directed to the case of realizing the document important item extraction device on the data relay device (a configuration in which it is independent from the client utilized by the user). Also, in this third embodiment, in addition to storing the important items extracted by the document important items extraction device for each user separately, a function for adding and changing an access permission list corresponding to these important items is provided, In this way, the important items extracted and stored for a particular user can be shared among other users. Such a document important item extraction device will be described in the embodiment 3-3 described below. The embodiment 3-3 is directed to the case where the document important item extraction device is realized on the data transmission and reception device. Also, in this third embodiment, a function for enabling the sharing of common important items among users in the case where the identical important items are extracted from the identical structured document by a plurality of user requests. Such a document important item extraction device will be described in the embodiment 3-4. The embodiment 3-4 is directed to the case where the document important item extraction device is realized on the data relay device. (Embodiment 3-1) FIG. 23 shows an exemplary configuration of a document important item extraction device 10400 according to this embodiment 3-1, which comprises a user interface unit 10401, a user authentication unit 10402, a structured document request reception unit 10403, | ||||||