JP2001159998A - Web contents cache system, its method and recording medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Web contents cache system by which a required cache storage capacity is reduced and also a retrieval speed is improved. SOLUTION: The system is provided with a cache storage part for storing URL, the last reference date and its contents, a keyword storage part for storing a keyword included in the contents together with the number of its reference times, a cache retrieving means for receiving URL from an input device, inspecting whether the URL is registered in the cache storage part or not and outputting the contents from the cache storage part to an output device, a keyword register means for reading the contents of URL in the case it is not registered extracting the keyword, registering the contents of the URL in the cache storage part and registering the extracted keyword in the keyword storage part and a cache erasing means for erasing contents information from the cache storage part by referring to the last reference date of the contents in the cache storage part and to the number of keyword reference times in the keyword storage parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a WWW (World WWW).
ide Web) Regarding the browser cache system,
In particular, the present invention relates to control for deleting content in a cache.

[0002]

2. Description of the Related Art Web connected via the Internet
In a system for browsing the content of the server b with the browser of the client terminal, the content acquired from the web server is retained for a certain period of time in, for example, a proxy server or a cache on the client side in order to speed up the content reference. The system is widespread.

[0003] A conventional Web content cache system has, as a general configuration, a cache storage unit, a cache registration unit, and a cache deletion unit, and when a content of a designated URL is registered in the cache storage unit. Output the content from the cache storage unit, and if the content of the specified URL is not registered in the cache storage unit, newly acquire and output the content of the URL, and the cache registration unit The acquired content is registered in the cache storage unit.

[0004] The cache registration means registers the content in the cache storage unit up to a predetermined memory capacity, for example, and when the memory capacity is exceeded, the cache deletion means deletes the content from the cache storage unit. At this time, the cache deletion unit deletes the least referenced content from the cache storage unit using the last reference date and time of the content registered in the content (date and time information of the last reference).

[0005]

However, the above-mentioned conventional system has the following problems.

[0006] The first problem is that the memory capacity of the cache increases.

[0007] The reason is that the cache deletion means has only a simple deletion function, so that it is necessary to set a large cache capacity in order to maintain high-speed content reference. is there.

A second problem is that it is not possible to quickly refer to important contents that have not been referenced for a long time.

[0009] The reason is that it is determined whether or not to delete the content from the cache using only the last reference date and time of the content.
This is because content that has not been referenced for a long time is deleted from the cache.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to reduce the required storage capacity of a cache and to improve a search speed in a Web content cache system method and recording. To provide a medium.

[0011]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a Web system for accelerating access to Web contents.
b In the content cache system, the content cache system includes means for deleting the content from the cache using the number of times of reference to the keyword included in the content.

[0012] In the present invention, when the access status of the content does not reach a predetermined criterion and the number of times of reference to a keyword included in the content is less than a predetermined value,
Deleting the content from the cache;

[0013]

Embodiments of the present invention will be described. The present invention, in one of its preferred embodiments,
Referring to FIG. 1, a URL (Uniform Resource Locator) of the content to be registered in the cache, last referenced date and time information referred to, and the cache storage unit (31) storing the content are included in the content in the cache. A keyword storage unit (32) for storing a keyword together with the number of times of reference, and a URL from the input device (1) are received, and it is checked whether the URL is stored in the cache storage unit (31). If the URL is stored in the cache storage unit (3), the cache search unit (21) that outputs the content from the cache storage unit (31) to the output device (4).
If the URL is not stored in 1), the content is acquired from the position specified by the URL, the keyword included in the content is extracted, and the URL is stored in the cache storage unit (31).
In addition to registering the contents of the RL, the extracted keywords are registered in the keyword storage unit (32).
A keyword registration unit (22) for setting the number of times of reference to an initial value “1” and outputting the content;
It is activated every predetermined period, and refers to the last reference date and time information of the content in the cache storage unit (31) and the number of times of reference to the same keyword as the keyword of the content by referring to the keyword storage unit (32). A cache deletion unit (23) for deleting, from the cache storage unit (31), the content in which the content has not been referred to for a predetermined period and the number of times of reference to the keyword included in the content is equal to or less than a predetermined value.

In an embodiment of the present invention having such a configuration, even if the access status of the content does not reach the predetermined criterion, if the content includes a keyword whose reference count exceeds the predetermined value, the content is read from the cache. Not deleted. Hereinafter, the operation of the embodiment of the present invention will be described.

[0015] For example, "http://www.nec.co.jp/" is given as a URL inputted from the input device (1), and the contents include "computer" as a keyword. I do. Cache search means (21)
Checks whether or not this URL "http://www.nec.co.jp/" is stored in the cache storage unit (31). If the URL is stored in the cache storage unit (31), the content is checked. Is output to the output device (4).

If the content is not stored in the cache storage unit (31), the content at the position specified by the URL is read out to extract a keyword, and the cache registration unit (22) reads the content from the cache storage unit (31). To http: // w
ww.nec.co.jp/ ”content, keyword storage (3
Register “Computer” in 2). The keyword storage unit (32) includes a column (information field) of a keyword and the number of times of reference for each keyword. The keyword “computer” is added, and the number of times of reference is set to “1”. On the other hand, when the keyword of “computer” is already registered in the keyword storage unit (32), the number of times of reference to the keyword of “computer” is incremented by one.

The cache deletion means (23) is started periodically, and includes a keyword included in the contents in the cache storage unit (31), the last reference date and time, and the word storage unit (3).
2) to delete the contents of the cache storage unit (31).

For example, if the user refers to a lot of contents unrelated to the keyword “computer” and does not refer to the contents including the keyword “computer” with little or no content, “http://ww.nec.co.jp The content "/" is deleted from the cache storage unit (31).

Thus, without carelessly increasing the cache capacity of the Web contents, the Web contents that the user is interested in can be held in the cache and the reference of the contents can be speeded up.

In the present invention, the URL of the content to be registered in the cache, the last reference date and time information, the cache storage unit (31) for storing the content, and the keyword included in the content to be registered in the cache together with the number of times of reference. A keyword storage unit (32) for storing;
In an information processing apparatus including a storage device (3) including a storage device (3), an input device (1), an output device (4), and a data processing device (2) controlled by a program, a URL is input from the input device (1). And checks whether or not the URL is registered in the cache storage unit. If the URL is registered in the cache storage unit (31), a search process for outputting the content from the cache storage unit (31) to the output device ( If the URL is not registered in the cache storage unit (31), the content is read from the position specified by the URL,
A registration process of extracting a keyword, registering the content of the URL in the cache storage unit, and registering the extracted keyword in the keyword storage unit (32) (processing of the cache registration unit 22); Last reference date and time information of the content of
Referring to the keyword reference count in 2), if the content in the cache storage unit (31) is not referred to for a predetermined period and the reference count of the keyword included in the content is equal to or smaller than a predetermined value, Each process of deleting content information from the cache storage unit (31) (the process of the cache deleting unit 23) is realized by a program executed by the data processing device (2). In this case, the medium (semiconductor memory, CD-ROM, DVD (digital versatile digital
sk) and a magnetic recording medium such as FD or MT), or a communication medium at the time of download from the server, and installs the program in the information processing device via a reading device or a communication device, and executes the execution format of the program. The present invention can be implemented by loading the data into the main memory of the data processing device and executing the data.

Further, in the present invention, a cache storage unit (31) for storing the URL of the content to be registered in the cache, last reference date and time information, and the content,
A classification information storage unit (33) for storing the classification information of the content registered in the cache; and a keyword storage unit (32) for storing the keywords included in the content registered in the cache together with the number of times of reference in the classification unit. An information processing device including a storage device (6) provided with an input device (1), an output device (4), and a data processing device (5) receives a URL from the input device (1), and receives the URL. Is checked in the cache storage unit (31), and if it is registered in the cache storage unit, a search process (cache search) for outputting the content from the cache storage unit (31) to the output device (4) Means 21
If the URL is not registered in the cache storage unit (31), a classifying process of reading the content from the position specified by the URL and registering the classifying information of the content (the process of the content classifying unit 24) )When,
A registration process (processing of the cache registration unit 22) for extracting a keyword from the content, registering the content of the URL in the cache storage unit, and registering the extracted keyword in the keyword storage unit (31), and storing classification information The content information is extracted from the cache storage unit (31) for each classification stored in the unit (33), and the last reference date and time of the content in the cache storage unit (31) and the keyword of the keyword in the keyword storage unit (32) are read. By referring to the reference count, the cache storage unit (3) stores information of the content in which the content has not been referred to for a predetermined period and the reference count of a keyword included in the content is equal to or less than a predetermined value.
Each processing of the deletion processing (processing of the cache deletion unit 25) to delete from 1) is realized by a program executed by the data processing device (2). In this case, a medium (semiconductor memory, CD-ROM,
DVD (digital versatile disk), FD, MT
Magnetic recording medium, etc.), or from a communication medium at the time of download from the server, via a reading device or a communication device,
The present invention can be implemented by installing a program in an information processing apparatus, loading an execution format of the program into a main memory of a data processing apparatus, and executing the program.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to describe the above-mentioned embodiment of the present invention in more detail, an embodiment of the present invention will be described.

FIG. 1 is a diagram showing the configuration of the first embodiment of the present invention. Referring to FIG. 1, a system according to a first embodiment of the present invention includes an input device 1 such as a web browser,
It includes a data processing device 2 that operates under program control, a storage device 3, and an output device 4 such as a Web browser.

The storage device 3 includes: a cache storage unit 31;
And a keyword storage unit 32.

The cache storage unit 31 stores a URL, its contents, and the last reference date and time.

The keyword storage unit 32 stores the keywords held by the contents in the cache storage unit 31 and the number of times of reference.

The data processing apparatus 2 includes a cache search unit 21, a cache registration unit 22, and a cache deletion unit 23.

The cache search means 21 uses the URL provided from the input device 1 as a key and
1 is searched for the content stored therein.

When the cache search unit 21 fails to search the content, the cache registration unit 22 actually reads the content, extracts a keyword from the content, and stores the URL of the content, the reference date and time, and the content in the cache storage unit 31. After registering and registering the keyword in the keyword storage unit 32, the content is output to the output device 4. When registering the content in the cache storage unit 31, it is also registered that the keyword extracted from the content is that of the content (it is not necessary to re-extract the keyword for the content).

The cache deletion means 23 is periodically started and deletes the contents of the cache storage unit 31 using the keyword included in the contents in the cache storage unit 31 and the last reference date / time word storage unit 32.

FIGS. 2 and 3 are flowcharts for explaining the operation of the first embodiment of the present invention. The operation of the first exemplary embodiment of the present invention will be described in detail with reference to FIGS.

First, the URL given from the input device 1
Is supplied to the cache search means 21. The cache unit 21 checks whether the URL is stored in the cache storage unit 31 (steps A1 and A2 in FIG. 2).

If the URL has been stored in the cache storage unit 31, the last reference date and time in the cache storage unit 31 and the number of keyword references in the keyword storage unit 32 are updated (step A7), and step A6 in FIG. Move to

Next, in FIG. 2, when it is determined in step A2 that the URL is not stored in the cache storage unit 31, the content indicated by the URL is transmitted by the HTTP protocol or the like via the Internet (not shown). It is actually read (step A3).

A keyword is extracted from the read content (step A4).

The content is registered in the cache storage unit 31 together with the URL, and the extracted keywords are registered in the keyword storage unit 32 (step A5).

Then, the contents are output to the output device 4 (step A6).

The cache deleting means 23 is started periodically and reads out the contents of the cache storage unit 31.
(Steps A10 and A11 in FIG. 3).

The keyword of the read content and the last reference date and time are extracted (step A12).

The number of times of reference to the keyword in the keyword storage unit 32 equal to the extracted keyword is extracted, and the number of times of reference to the keyword is smaller than a predetermined reference value.
From the difference between the current date and time of the system clock and the last reference date and time,
It is checked whether the elapsed time (access time interval) from the last reference date and time is longer than a predetermined time (step A).
13).

If the number of times the keyword is referenced is equal to or less than a predetermined reference value and the elapsed time from the last reference date and time is longer than the predetermined time, information on the URL (URL, last reference date and time, content ) Is deleted from the cache storage unit 31 and the keyword storage unit 32.
(Step A14).

Next, the operation of the first embodiment of the present invention will be described with reference to a specific example.

As shown in FIG. 4, the cache storage unit 31
Has registered therein content information that has been read so far.

The cache search means 21 receives the URL “http://www.nec.co.jp/” from the input device 1 and searches the cache storage unit 31.

In this case, as shown in FIG. 4, since the URL “http://www.nec.co.jp/” is not stored in the cache storage unit 31, the cache search unit 21 determines that the search cannot be performed. Judgment (Step A1 and Step A in FIG. 2)
2).

Next, the cache search means 21 actually reads the content (step A3) and extracts "computer" which is a keyword of the content (step A4). The content is registered in the cache storage unit 31 (the URL “http://www.nec.co.jp/” and the reference date and time “1999/9/31” are also registered), and the extracted keyword “computer” is used as the keyword. The information is registered in the storage unit 32 (step A5). Then, the content is output to the output device 4.
(Step A6). If the keyword “computer” has already been registered in the keyword storage unit 32, one is added to the column of the number of times of reference of the keyword “computer” in the keyword storage unit 32.

The cache erasing means 23 started periodically determines whether or not to delete the cache based on the last reference date and time of the contents in the cache storage unit 31 and the keywords included in the contents (step A in FIG. 3).
10, A11, A12 and A13).

For example, the threshold value for the keyword is “1”
Assuming that the date when the cache deletion unit 23 is executed with the time being “1 month” is September 31, 1999, the URL “http: /” with “automobile” as a keyword
/www.bbb.co.jp/ "is deleted (Fig. 3
Step A14). This is because the URL “http://www.bbb.co.jp/” registered in the cache storage unit 31 has a last reference date and time of August 10, 1999, and refers to the keyword “car” of the content. Since the number of times is “1”, the number of times of reference to the keyword is equal to or less than a predetermined reference value (= 1), and the elapsed time from the last reference date and time is longer than a predetermined time (= 1 month). This is because the long deletion condition is satisfied.

U registered in the cache storage unit 31
RL "http://www.aaa.co.jp/", URL "http: // www.
ccc.co.jp/ "has the last reference date and time of August 10, 1999, respectively. However, since the number of references to the keyword" science "of these contents is" 4 ", the information of these contents is It is not deleted from the cache storage unit 31.

Next, a second embodiment of the present invention will be described. FIG. 5 is a diagram showing the configuration of the second embodiment of the present invention. Referring to FIG. 5, according to a second embodiment of the present invention, a data processing device 5 includes a content classification unit 24 in addition to the configuration of the data processing device 2 of the first embodiment shown in FIG. The storage device 6 further includes a classification information storage unit 33. In the following, the differences between the second embodiment of the present invention and the first embodiment will be described.

The contents classifying means 24 classifies the read contents by using general functions. For example,
A search service with a well-known classification function
(Such as "www.yahoo.co.jp") or use a tool for classification.

In this embodiment, the keyword storage unit 32 stores a keyword for each classification, and when checking the keyword, the cache deletion unit 25 checks the keyword storage unit 32 stored for each classification.

FIGS. 6 and 7 are flow charts for explaining the operation of the second embodiment of the present invention. The operation of the second exemplary embodiment of the present invention will be described with reference to FIGS.

Steps A1-A4, A6 and A7 in FIG.
The operations of the cache search means 21 in this embodiment and the operations of steps A10, A12 and A14 in FIG. 7 are the same as those of the cache search means 21, cache registration 22 and cache deletion 23 in the first embodiment. The description is omitted because they are the same.

In the first embodiment, the keyword storage unit 32 stores the keywords for all of the cache storage units 31. However, in the second embodiment of the present invention, the keyword storage unit 32 stores the keywords in classification units. Remember.

The contents classifying means 24 classifies the read contents by using general functions. For example,
A search service with a well-known classification function
(Such as "www.yahoo.co.jp") or a tool for classification (step B1 in FIG. 6). The classified information is stored in the classification information storage unit 33 (Step B2).

Next, the cache deleting means 25 extracts the contents for each classification (steps B10 and B1 in FIG. 7).
1, and A11).

In the process of examining whether or not to delete from the cache, the keyword to be compared is examined not as the keyword storage unit 32 but as the classification information storage unit 33 (step B12).

Next, a second embodiment of the present invention will be described with reference to a specific example.

For example, as shown in FIG. 8, it is assumed that information on the content that has been read so far is registered in the cache storage unit 31, the keyword storage unit 32, and the classification information storage unit 33, respectively.

The cache search unit 21 receives the URL “http://www.nec.co.jp/” from the input device 1 and searches the cache storage unit 31.

Here, the UR is stored in the cache storage unit 31.
Since L “http://www.nec.co.jp/” is not stored, the cache search unit 21 determines that the search is impossible (steps A1 and A2 in FIG. 6).

Next, the cache search means 21 actually reads out the contents (step A3) and performs classification using a known method (step B1). In this case, the content is classified as “science”.

Next, "computer" which is a keyword of the read content is extracted (step A4), the content is registered in the cache storage unit 31, the keyword is registered in the keyword storage unit 32, and the classification information is stored in the classification information storage unit. 33 (step B2) and output to the output device 4.
(Step A6).

The cache deletion unit 25 determines whether or not to delete the cache from the classification information storage unit 33 based on the last reference date and time of the contents in the cache storage unit 31 and the keywords included in the contents (step B in FIG. 7).
10, B11, A10, A12 and B12).

For example, the threshold value for the keyword is “1”
Assuming that the time for defining the non-access period is one month, and the date on which the cache deletion unit 23 is executed is September 31, 1999, the content classification is “vehicles” and the keyword reference count is The cache information of “http://www.ddd.co.jp/” including the keyword “bicycle” of “1” is deleted (step A14 in FIG. 7).

The classification of the content is “vehicles”, “http://www.bbb.co.jp/” including the keyword “car” having the keyword reference frequency of “3”, and the classification of the content is “science”. Yes, "http://www.aaa.co.jp/" including the keyword "science" with a keyword reference count of "4", a keyword whose content classification is "science" and the keyword reference count is "2""Http://www.cc" including "automobile"
c.co.jp/ "is not deleted. As described above, by using the classification information, the content to be deleted can be determined more accurately.

In the first and second embodiments of the present invention, the cache search means 21 and the cache registration means 2
2. The processes and functions of the cache deletion units 23 and 25 and the content classification unit 24 are realized by a program executed by the data processing device.

[0069]

As described above, according to the present invention, the following effects can be obtained.

The first effect of the present invention is that the storage capacity of the cache can be reduced.

The reason is that, in the present invention, not only the time but also the keyword included in the content is used to discard the cache, and the content that is not likely to be read again is deleted from the cache.

A second effect of the present invention is that the search speed can be improved by using a cache.

The reason is that, in the present invention, not only the time but also the keyword contained in the content is used to destroy the cache, so that the content that is highly likely to be reused can be held in the cache.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention.

FIG. 2 is a flowchart showing a processing procedure according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a processing procedure according to the first embodiment of the present invention.

FIG. 4 is a schematic diagram for specifically explaining the first embodiment of the present invention.

FIG. 5 is a diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure according to a second embodiment of the present invention.

FIG. 7 is a flowchart showing a processing procedure according to a second embodiment of the present invention.

FIG. 8 is a schematic diagram for specifically explaining a second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 input device 2 data processing device 3, 6 storage device 4 output device 21 cache search means 22 cache registration means 24 content classification means 23, 25 cache deletion means 31 cache storage unit 32 keyword storage unit 33 classification information storage unit

Claims (10)

[Claims] 1. A Web content cache, comprising: means for determining content to be deleted from the cache based on an access status of content registered in the cache and a reference count of a keyword included in the content. system. 2. When the access status of the content does not reach a predetermined reference and the number of times of reference to a keyword included in the content is equal to or less than a predetermined value, the content is cached. 2. The Web content cache system according to claim 1, wherein the Web content cache system deletes the content. 3. When deleting a content registered in a cache, an access status of the content,
A Web content cache control method, wherein a content to be deleted from the cache is determined based on a reference count of a keyword included in the content. 4. When the access status of the content does not reach a predetermined reference and the number of times of reference to a keyword included in the content is equal to or less than a predetermined value, the content is cached. 4. The web content cache control method according to claim 3, wherein the web content cache control method deletes the content. 5. A designated URL (Uniform Resource L)
ocator), the content is output from the cache when the content is registered in the cache, and when the content of the URL is not registered in the cache, the content of the URL is newly obtained and A web content cache system for registering and outputting the content in the cache, extracting a keyword included in the content to be registered in the cache, storing and managing the extracted keyword, and for the content already registered in the cache, Web content cache system comprising means for determining content to be deleted based on the access information and the number of times a keyword is referenced. 6. A designated URL (Uniform Resource L)
ocator), the content is output from the cache when the content is registered in the cache, and when the content of the URL is not registered in the cache, the content of the URL is newly obtained and Means for acquiring classification information of contents registered in the cache, extracting a keyword included in the contents registered in the cache, and classifying the extracted keywords into the classification of the contents. Means for storing and managing each content, and for content already registered in the cache, for each classification, means for determining content to be deleted based on the access information of the content and the number of times of reference to the keyword. We feature b Content cache system. 7. The URL of the content to be registered in the cache
(Uniform Resource Locator), last reference date and time information of the content, a cache storage unit for storing the content, and a keyword storage unit for storing a keyword included in the content registered in the cache storage unit together with the number of times of reference. And receives a URL from the input device, checks whether the URL is registered in the cache storage unit, and outputs the content from the cache storage unit to the output device if the URL is registered in the cache storage unit. If the URL is not registered in the cache storage unit, obtains a content from a position specified by the URL, extracts a keyword included in the content, And register the contents of the URL, and to the keyword storage unit. A cache registration unit that registers the extracted keyword and outputs the content to the output device; a last reference date and time information of the content in the cache storage unit; and a reference count of the keyword in the keyword storage unit. A cache deletion unit configured to delete, from the cache storage unit, content information in which the content has not been referred to for a predetermined period and the number of times of reference to a keyword included in the content is equal to or less than a predetermined value. An information processing apparatus, comprising: 8. The URL of the content to be registered in the cache
(Uniform Resource Locator), last reference date and time information of the content, a cache storage unit that stores the content, a classification information storage unit that stores classification information of the content registered in the cache storage unit, and the cache A keyword storage unit that stores a keyword included in the content registered in the storage unit together with the number of references in a classification unit, a URL received from the input device, and a check is made as to whether the URL is registered in the cache storage unit, A cache search unit that outputs the content from the cache storage unit to an output device when the URL is registered in the cache storage unit; and a URL that is specified by the URL when the URL is not registered in the cache storage unit. Content from the location to be registered and register the classification information of the acquired content Extracting a keyword from the acquired content, registering the content of the URL in the cache storage unit, registering the extracted keyword in the keyword storage unit, and transmitting the content to the output device. Cache registering means for outputting, for each classification stored in the classification information storage unit, extracting information of the content from the cache storage unit, final reference date and time information of the content in the cache storage unit, By referring to the number of times of reference to the keyword, the information of the content in which the content has not been referred to for a predetermined period of time and the number of times of reference of the keyword included in the content is equal to or less than a predetermined value is cached. A cache deleting means for deleting from the storage unit; The information processing apparatus characterized by being e. 9. The URL of the content to be registered in the cache
(Uniform Resource Locator), a cache storage unit for storing last reference date and time information of the content, the content, and a keyword storage unit for storing a keyword included in the content registered in the cache storage unit together with the number of times of reference. , An input device, an output device, and a data processing device, comprising: (a) receiving a URL from the input device;
Check whether is registered in the cache storage unit, if it is registered in the cache storage unit,
(B) when the URL is not registered in the cache storage unit, the content is read from a location specified by the URL, and a keyword is input. Extract and register the content of the URL in the cache storage unit,
A registration process of registering the extracted keyword in the keyword storage unit; and (c) determining the content by referring to the last reference date and time information of the content in the cache storage unit and the number of times of reference of the keyword in the keyword storage unit A process of deleting from the cache storage unit information of a content that is not referred to for a period and for which the number of times of reference to a keyword included in the content is less than a predetermined value; and a process of (a) to (c) of And a recording medium storing a program to be executed by the data processing device. 10. The UR of the content to be registered in the cache
L (Uniform Resource Locator), last reference date and time information of the content, a cache storage unit for storing the content, a classification information storage unit for storing classification information of the content registered in the cache storage unit, and the cache A storage device including a keyword storage unit that stores a keyword included in the content registered in the storage unit together with the number of references in a classification unit, an information processing device including an input device, an output device, and a data processing device (A) receiving a URL from the input device;
Check whether is registered in the cache storage unit, if it is registered in the cache storage unit,
(B) when the URL is not registered in the cache storage unit, obtains the content from a position specified by the URL; (C) extracting a keyword from the acquired content, registering the URL content in the cache storage unit, and registering the extracted keyword in the keyword storage unit. (D) for each category stored in the category information storage unit, extracting content information from the cache storage unit, and obtaining the last reference date and time information of the content in the cache storage unit, and The content is determined in advance by referring to the (A) through (d): a deletion process of deleting from the cache storage unit information of content that has not been referred to for a predetermined period and in which the number of times of reference to a keyword included in the content is less than a predetermined value. A) a recording medium on which a program for causing the data processing device to execute each process of the above) is recorded.