JP4881196B2 - Information retrieval apparatus and information retrieval program - Google Patents

Description

  The present invention relates to a technique for searching a database using a search logical expression including a keyword.

  In recent years, the amount of information has increased explosively in various fields. Depending on the field, the amount of information has reached from the gigabyte order to the terabyte order. For this reason, it is becoming difficult to search for desired information from such a vast amount of information.

  When searching for the desired information, a search logical expression (or simply “search expression”) is often generated. For example, when searching for a site on the Web, a plurality of keywords are often input. In order to search for a site including all of the plurality of input keywords, an AND logic search expression is generated. Further, in order to search for a site including any one of a plurality of input keywords, an OR logic search expression is generated. In addition, complex search expressions that include both AND logic and OR logic may be generated.

  In addition, due to the increase in search users, a huge number of search requests are given to the search engine. For this reason, the search engine is required to respond to a large number of search requests at high speed. Here, the search process usually includes a process of searching for each keyword included in the search logical expression and a process of evaluating the search logical expression based on the result of the keyword search. “Evaluation of search logical expression” means a process of determining whether or not a condition represented by the search logical expression is satisfied for each document to be searched. For example, in the evaluation for the search logical expression “a & b”, it is determined whether or not each of the documents to be searched includes both the keyword a and the keyword b. Various proposals have been made regarding techniques for speeding up keyword searches. However, regarding the evaluation of the search logical expression, a technique for greatly reducing the processing time has not been proposed, and there is a lot of room for improvement.

  FIG. 10 is a diagram illustrating an example of a conventional information search apparatus. The information search apparatus illustrated in FIG. 10 includes a mediation apparatus 101, a search apparatus 102, and an evaluation apparatus 103. The intermediary device 101 accepts a search logical expression input by each user, creates a query table 104, and sends a search request to the search device 102. In the query table 104, keywords included in the received search logical expression are registered, and each keyword is managed to determine whether or not it has been hit in the database search. The search request includes a query list that lists keywords included in the received search logical expression.

  The search device 102 accesses the database 105 to perform a search for each keyword included in the query list, and returns the search result to the mediation device 101. Then, the mediation apparatus 101 updates the query table 104 according to the search result. The evaluation device 103 refers to the query table 104 and evaluates each search logical expression. For example, the search logical expression input by Mr. A is “red & car”. This search logic formula includes “red” and includes “car”. "Means. However, in the embodiment shown in FIG. 10, “red” is hit, but “car” is not hit. Therefore, this search logical expression is evaluated as “false (no corresponding information)”. On the other hand, the search logical expression input by Mr. C is “sea & mountain”. This search logical expression includes “sea” or includes “mountain”. "Means. Therefore, this search logical expression is evaluated as “true (with corresponding information)”. Then, this evaluation result (or information obtained from this search result) is provided to each user.

  FIG. 11 is a flowchart showing the operation of the information search apparatus shown in FIG. In step S101, keywords included in the given search logical expression are extracted to create a query table. In step S102, the database is searched for keywords registered in the query table. In step S103, the query table is updated according to the keyword search result. In step S104, logical evaluation is performed for each search logical expression.

  As described above, in the information search apparatus shown in FIG. 10, all the search logical expressions are logically evaluated. For this reason, there is a limit to shortening the search time. For example, Patent Documents 1 and 2 are known as techniques for shortening the information search time.

The information search apparatus described in Patent Document 1 generates an optimized search logical expression by simplifying a union of a plurality of search logical expressions, and searches for necessary information using the optimized search logical expression. And in patent document 1, the case where the search logical expressions of users A, B, and C are “a + b”, “ab + c”, and “a + b + c”, respectively, is described as an example. In this case, the optimized search logical expression is obtained as follows.
(A + b) + (ab + c) + (a + b + c)
→ a + ab + b + c + (a + b + c)
→ a + b + c + (a + b + c)
→ a + b + c
Then, the search results for the users A to C are acquired using the optimized search logical expression “a + b + c”, and then individual searches for the users A to C are performed from the search results.

Patent Document 2 describes a technique for reducing the amount of processing by predicting the appearance frequency of each keyword constituting a search logical expression and performing a search process from a keyword with a low appearance frequency. For example, it is assumed that the given search logical expression is “a & b”, and the filing frequency of the keyword b is lower than the appearance frequency of the keyword a. In this case, according to the procedure described in Patent Document 2, first, a search process is executed for the keyword b, and then a document including the keyword a is searched from documents hit for the keyword b.
JP-A-1-149125 JP-A-57-166668

  In the conventional search methods (including the methods described in Patent Documents 1 and 2), when the amount of information stored in the database to be searched is enormous, the search logical expression is complicated, or simultaneously processed When the number of search requests to be performed is large, the search logical expression cannot be evaluated efficiently. For this reason, even if the search time for each keyword is shortened, the time required for evaluating the search logical expression becomes relatively long, and the time required for obtaining the search result after the user inputs the keyword. Is not shortened so much.

  An object of the present invention is to provide an apparatus and a method for shortening a search time in an information search using a search logical expression including a keyword.

An information search apparatus according to the present invention includes an extraction unit that extracts search elements from a plurality of search logical expressions, a search unit that performs a database search for the search elements, and the plurality of search logical expressions, respectively, A simplification unit that generates a plurality of provisional logical expressions corresponding to a search logical expression, a first evaluation unit that performs logical evaluation on the temporary logical expression according to a search result of the search unit, and the first evaluation unit And a second evaluation unit that performs logical evaluation on the search logical expression corresponding to the temporary logical expression evaluated as the first evaluation value.

  In the present invention, logical evaluation is not performed for all search logical expressions, but logical evaluation is performed only for a search logical expression in which the corresponding temporary logical expression is evaluated as the first evaluation value. Is shortened. The provisional logical expression is obtained by simplifying the search logical expression, and the logical evaluation is simple.

  In the information search apparatus, the simplification unit may convert the provisional logical expression defined only by an OR condition of the search logical expression. The provisional logical expression described only by the OR condition can be evaluated for logic only by checking whether or not the keyword included in the expression is hit.

  The information search apparatus may further include a management unit that manages each of the plurality of temporary logical expressions with 1-bit temporary result information. In this case, the first evaluation unit updates the corresponding temporary result information managed by the management unit according to whether or not a search condition defined by the plurality of temporary logical expressions is satisfied. . In addition, the second evaluation unit refers to the management unit and performs logical evaluation only on the search logical expression corresponding to the provisional logical expression that satisfies the search condition.

  According to the present invention, in the information search using the search logical expression including the keyword, the search time is shortened.

  FIG. 1 is a diagram showing a configuration of an information search apparatus according to an embodiment of the present invention. As shown in FIG. 1, the information search device according to the embodiment includes an intermediary device 1, a search device 2, a temporary evaluation device 3, and an evaluation device 4. In FIG. 1, only the main part of the information search apparatus of the embodiment is illustrated.

  This information search device searches the database 11 in response to a given search request. The database 11 is composed of one or a plurality of information recording devices and stores various information. Hereinafter, each search object stored in the database 11 is referred to as a “record”. Each “record” corresponds to, for example, one page on the Web or one document.

  The intermediary device 1 accepts a search request input by each user. The search request includes one or more keywords. These keywords constitute a logical expression using an OR condition and / or an AND condition in accordance with a user instruction. Hereinafter, the logical expression generated in this way is referred to as “search logical expression”. When the search request includes only one keyword, the one keyword becomes a search logical expression.

  In this embodiment, “red & car”, “brush or pen & hair”, and “sea or mountain” are input from A, B, and C as search logical expressions. “Red & car” includes “red” and includes “car”. "Means. "Brush or pen & hair" includes "" brush "or includes both" pen "and" hair ". "Means. "Sea or mountain" includes "" sea "or includes" mountain ". "Means.

The intermediary device 1 processes a predetermined number of search requests determined in advance in parallel. In the embodiment shown in FIG. 1, three search requests (ie, three search logical expressions) are processed in parallel.
The intermediary device 1 extracts keywords from a plurality of search logical expressions to be processed in parallel. In this embodiment, seven keywords “red”, “car”, “brush”, “pen”, “hair”, “sea”, and “mountain” are extracted. Note that a method for extracting a keyword from a search logical expression can be realized by a known technique, and thus description thereof is omitted. Then, the intermediary device 1 generates a query list including all the extracted keywords and transmits it to the search device 2.

  The search device 2 performs a keyword search for each record stored in the database 11. Here, a case where a search is executed for a certain record will be described. That is, it is checked whether or not each of the seven keywords is included in the search target record. In this example, “red”, “sea”, “mountain”, and “hair” were hit, but “car”, “brush”, and “pen” were not hit. Then, the search device 2 returns the search result to the mediation device 1. The keyword search method is not particularly limited, and any known technique can be used.

  The intermediary device 1 creates a query table 21. In the query table 21, keywords extracted from the search logical expression are registered. Then, a search result by the search device 2 is written for each registered keyword. In FIG. 1, “◯” marks are written for keywords (red, sea, mountain, hair) hit in the database 11.

Further, the intermediary device 1 generates a corresponding temporary logical expression by simplifying the search logical expression input by each user. Hereinafter, a method for generating the temporary logical expression Z1 ′ from the search logical expression Z1 will be described. Here, it is assumed that the following search logical expression Z1 is given.
Z1 = ((((A1 or A2) and (A3 or A4 or A5) and A6) or (B1 and B2)) and (C1 or C2)
In the simplification procedure, the conversion is performed so as to satisfy the requirement of “Z1 = 1”. Specifically, as shown in FIG. 2, the logical expression is transformed by deleting keywords connected by the AND condition. That is, “A3 or A4 or A5” and “A6” are connected to “A1 or A2” under AND conditions. Therefore, both “A3 or A4 or A5” and “A6” are deleted. In addition, “C1 or C2” is connected to “B1 and B2” using an AND condition. Therefore, “C1 or C2” is also deleted. Furthermore, “B2” is connected to “B1” under an AND condition. Therefore, “B2” is also deleted. As a result, the following provisional logical expression Z1 ′ is obtained. Z1 '= A1 or A2 or B1
In this way, the provisional logical expression Z1 ′ is obtained by deleting the keyword connected by the AND condition in the search logical expression Z1. Therefore, the set of records satisfying the temporary logical expression Z1 ′ includes all the sets of records satisfying the search logical expression Z1. In the present invention, the search time is shortened by utilizing this property. That is, when extracting records satisfying the search logical expression Z1, first, records satisfying the temporary logical expression Z1 ′ are extracted. Here, since the provisional logical expression Z1 ′ is described only by the OR condition, it is easy to determine whether or not each record satisfies the logic. Subsequently, a record satisfying the search logical expression Z1 is extracted from a set of records satisfying the temporary logical expression Z1 ′. At this time, the set to be searched is reduced by the provisional logical expression Z1 ′ described above. For this reason, even if the search logical expression Z1 is complicated, the search time is shortened.

  With the above simplification, the search logical expression “red & car” input by Mr. A is converted into a temporary logical expression “red”. In addition, the search logical expression “brush or pen & hair” input by Mr. B is converted into a temporary logical expression “brush or pen”. However, since the search logical expression “sea & mountain” input by Mr. C does not include an AND condition, the temporary logical expression is the same as the search logical expression.

  The intermediary device 1 creates a temporary hit table 22 for managing the temporary logical expressions generated as described above. The temporary hit table 22 manages each temporary logical expression with a 1-bit temporary result flag. In FIG. 1, the temporary result flag is represented by “◯” and “×”.

  The query table 21 and the temporary hit table 22 configured as described above are updated as follows. Here, a process for a certain record (that is, a certain document stored in the database 11) will be described.

  (1) When the search device 2 detects that “red” is included in the document, the search device 2 notifies the mediation device 1 to that effect. Upon receiving this notification, the intermediary device 1 sets a hit flag corresponding to “red” in the query table 21 and sets a temporary result flag corresponding to “Mr. A” in the temporary hit table 22. In FIG. 1, the mark “◯” indicates that the flag has been set.

  (2) When the search device 2 detects that “sea” is included in the document, the search device 2 notifies the intermediary device 1 to that effect. Upon receiving this notification, the intermediary device 1 sets a hit flag corresponding to “Sea” in the query table 21 and sets a temporary result flag corresponding to “Mr. C” in the temporary hit table 22.

(3) When the search device 2 detects that “red” is included in the document, the search device 2 notifies the mediation device 1 to that effect. In this case, the mediation apparatus 1 performs the same process as (1) above.
(4) When the search device 2 detects that “mountain” is included in the document, the search device 2 notifies the mediation device 1 to that effect. Upon receiving this notification, the intermediary device 1 sets a hit flag corresponding to “mountain” in the query table 21, and sets a temporary result flag corresponding to “Mr. C” in the temporary hit table 22.

  (5) When the search device 2 detects that “hair” is included in the document, the search device 2 notifies the mediation device 1 to that effect. Upon receiving this notification, the intermediary device 1 sets a hit flag corresponding to “hair” in the query table 21. However, since there is no provisional logical expression including “hair”, the provisional hit table 22 is not updated.

  Through the procedures (1) to (5), the query table 21 and the temporary hit table 22 are updated to the state shown in FIG. That is, in the query table 21, “1 (◯)” is set for “red”, “sea”, “mountain”, and “hair”, and “0 (no mark)” for “car”, “brush”, and “pen”. Is set. In the temporary hit table 22, “1 (◯)” is set for the temporary logical expressions corresponding to the search requests of Mr. A and Mr. C, and the temporary logical expression corresponding to the search request of Mr. B is set. “0 (×)” is set.

Here, the evaluation of the provisional logical expression will be described with reference to FIG. “Evaluation” means processing for determining whether or not there is a record satisfying the logical expression.
In a general evaluation procedure, a search result for each element (that is, a keyword) constituting a logical expression is held, and the logical expression is evaluated by executing a logical operation on the search result. On the other hand, in the information retrieval apparatus according to the present invention, when one or more of the elements constituting the temporary logical expression is hit using the fact that the temporary logical expression is described only by the OR condition. Is determined to be “true (logic is satisfied)”, and when no element is hit, it is determined to be “false (logic is not satisfied)”. This determination result (true / false) is written in the temporary hit table 22 as a 1-bit temporary result flag. That is, in the present invention, no logical operation is required when evaluating a provisional logical expression.

  The temporary evaluation device 3 refers to the temporary hit table 22 and determines a search request that needs to be evaluated from among the search requests input from each user. In the example shown in FIG. 1, “1 (◯)” is set for the provisional logical expressions of Mr. A and Mr. C. Therefore, in this case, the temporary evaluation device 3 determines that it is necessary to evaluate the search requests of Mr. A and Mr. C, and notifies the evaluation device 4 to that effect.

  Here, the operation of the provisional evaluation device 3 will be described with reference to FIG. Here, it is assumed that the temporary hit table 22 is a 32-bit register. In this case, 32 search requests (or 32 users) can be processed simultaneously. Then, it is assumed that a temporary result flag for the temporary logical expression corresponding to each user's search request is written in the corresponding bit of the 32-bit register.

  The temporary evaluation device 3 detects the bit position where “1” is written using the SCAN instruction. The SCAN instruction is an instruction supported by many CPUs. The value of each bit is checked in order from the most significant bit of the register, and the bit position where “1” is detected first is notified. The SCAN instruction also includes a procedure for clearing a bit where “1” is detected (that is, writing “0”). Therefore, by repeatedly executing this SCAN instruction, it is possible to detect a search request in which the temporary logical expression satisfies the search condition.

  The evaluation device 4 refers to the query table 21 and evaluates only the search request notified from the temporary evaluation device 3. In the example shown in FIG. 1, the logical evaluation is performed only for the search requests of Mr. A and Mr. C without evaluating the search request of Mr. B. At this time, Mr. A's search logical expression is “red & car”, and “car” is not hit, so it is evaluated as “false”. On the other hand, Mr. C's search logical expression is “sea or mountain” and is evaluated as “true”.

  The evaluation device 4 writes the above-described evaluation result in the hit table. As shown in FIG. 5, the hit table manages whether or not each user's search request hits each record. The number of users (search requests) managed by one hit table is, for example, the same as the number of bits of a register constituting the temporary hit table 22. Each time the evaluation device 4 evaluates each record, the evaluation device 4 writes the result in the hit table.

  When the logical evaluation of each search request is completed for all records, the hit table is completed. The information search apparatus according to the embodiment refers to the completed hit table and transmits information for identifying the hit record to each user or a part or all of the document corresponding to the record as a search result. In the example shown in FIG. 5, information for identifying the record 3 (or a part or all of the document corresponding to the record 3) is transmitted to the user A as a search result. Further, information for identifying the record 4 (or a part or all of the document corresponding to the record 4) is transmitted to the user C as a search result.

FIG. 6 is a flowchart illustrating the operation of the information search apparatus according to the embodiment. Note that the processing of this flowchart is executed when a search request is given from the user.
In step S1, keywords included in each search request are extracted. Here, a plurality of search requests (for example, search requests having the same number as the number of bits of the registers constituting the temporary hit table) are processed in a lump. In step S2, a query table is created. In step S3, a corresponding provisional logical expression is created by simplifying each search request, and a provisional hit table for managing evaluation for each provisional logical expression is created. Then, a search engine is activated to execute a search for each keyword extracted in step S1. Note that steps S1 to S4 are executed by the mediation apparatus 1.

Steps S5 to S11 are executed for each record. That is, steps S5 to S9 are repeatedly executed. In step S5, keyword search is executed for the designated record. Step S5 is executed by the search device 2. In step S6, the query table and the temporary hit table are updated according to the search result. Step S6 is executed by the mediation apparatus 1. In step S7, the temporary hit table is referred to search for a search request to be evaluated. Step S7 is executed by the provisional evaluation device 3. In step S8, logical evaluation is performed only for the search request specified in step S7. In step S9, the evaluation result is written in the hit table. Steps S8 to S9 are executed by the evaluation device 4.

When Steps S5 to S9 are executed for all records, the process proceeds to Step S12. In step S12, the hit table is referenced and the search result is transmitted to each user.
FIG. 7 is a diagram for explaining the processing amount of logic evaluation. The prior art is assumed to be the search method shown in FIGS. Further, FIG. 7 shows the processing amount per record.

  In the prior art, when the logic of each search request is evaluated, an evaluation process and a table update process are performed. The processing amount of the evaluation process corresponds to “the processing amount E of each search logical expression × the number of search requests”. The processing amount of the table update processing corresponds to “the processing amount G of the writing processing × the number of hits”.

  On the other hand, in the search method of the embodiment, when the logic of each search request is evaluated, an evaluation process, a temporary hit table search process, and a table update process are required. The processing amount of the evaluation processing corresponds to “the processing amount E of each search logical expression × the number of hits of the temporary logical expression”. Further, the processing amount of the search process corresponds to “the processing amount F of the table search process × the number of hits of the provisional logical expression”. Further, the processing amount of the table update processing corresponds to “processing amount G of writing processing × (number of hits + number of hits of provisional logical expression)”.

  In general, the amount of information stored in the database 11 is enormous. That is, the record number n is enormous. For this reason, unless the keyword included in the search request is a very common term, the hit rate in the keyword search should be considerably low. In other words, when searching all records in the database 11, it is considered that the provisional logical expression is determined to be “false” in most records. The logical evaluation is not executed for the search request for which the provisional logical expression is determined to be “false”. Therefore, in the information retrieval apparatus of the embodiment, the number of retrieval logical expressions that are actually evaluated is significantly smaller than that of the conventional technique.

  An example is shown. Here, 32 search requests are processed simultaneously. In addition, it is assumed that the target accumulated in the database is 1 million records. Furthermore, it is assumed that the average hit rate of each provisional logical expression is 0.1%. Then, according to the conventional search method, the number of evaluations of the search logical expression becomes 32 million (= 32 × 1 million). On the other hand, according to the search method of the embodiment, since the actual logical evaluation is performed only when the temporary logical expression is hit, the number of evaluations of the search logical expression is 32000 (= 32 × 1 million × 0.001). )

  In the search method of the embodiment, unlike the prior art, processing for updating the temporary hit table occurs. However, this processing only updates the corresponding bit of the register, and the amount of processing is sufficiently small compared with the logical evaluation of the search logical expression. Further, in the search method of the embodiment, unlike the conventional technique, a process for searching the temporary hit table occurs. However, this processing only refers to each bit of the register using a SCAN instruction or the like, and the amount of processing is sufficiently small compared with the logical evaluation of the search logical expression. Therefore, in the search method of the embodiment, although new processing occurs as compared with the conventional technique, the processing amount can be significantly reduced as the overall evaluation of the search logical expression. Thereby, the processing time of the whole search process is shortened.

  As described above, the present invention utilizes the fact that the number of hits is smaller than the number of search targets in many information searches (that is, the hit rate is low). In one embodiment, a temporary logical expression composed only of OR logic, which is a necessary condition for each search logical expression, is generated for a plurality of search requests, and 1 bit is assigned to each search request. When a keyword included in the temporary logical expression is hit, the search request corresponding to the temporary logical expression may also be hit, and the logical expression is evaluated for the search request. On the other hand, if the keyword included in the temporary logical expression does not hit, there is no possibility that the search request corresponding to the temporary logical expression will hit, so the logical expression is not evaluated for the search request. Therefore, the time required for evaluating the search logical expression hardly depends on the multiplicity or complexity of the search request, and depends on the keyword hit rate. Therefore, if the keyword hit rate is very low, the evaluation of the search logical expression can be realized within a period for executing one scan.

  FIG. 8 is a diagram for explaining the update of the query table 21 and the provisional hit table 22. In this embodiment, the query table 21 is provided with an area for writing position information for each registered keyword. The position information represents the position (address) where the temporary result flag corresponding to the temporary logical expression including the keyword is stored. This position information is set when a temporary logical expression is generated and a predetermined bit of the temporary hit table 22 is assigned. For example, when the temporary logical expression “red” is generated and the temporary result flag corresponding to the temporary logical expression is assigned to the Ath bit of the temporary hit table 22, the query table 21 stores “A” as the position information of the keyword “red”. Is set. Similarly, when the temporary logical expression “brush or pen” is generated and the temporary result flag corresponding to the temporary logical expression is assigned to the Bth bit of the temporary hit table 22, the keywords “brush” and “pen” are stored in the query table 21. "B" is set as the position information of "."

  If the table structure as described above is introduced, for example, when the keyword “red” is hit, a flag corresponding to “red” in the query table 21 is set to “1 (◯)” and the position information A Based on this, “1 (◯)” is written to the A-th bit in the temporary hit table 22.

  FIG. 9 is a block diagram of a computer that executes a program describing the functions of the present invention. The functions according to the present invention are realized by executing a program describing the above-described processing using a computer.

  The CPU 31 loads a program describing the above-described processing procedure from the storage device 32 to the memory 33 and executes it. The storage device 32 is a hard disk, for example, and stores the program. Note that the storage device 32 may be an external storage device connected to the computer 30. The memory 33 is, for example, a semiconductor memory and is used as a work area for the CPU 31.

  The recording medium driver 34 accesses the portable recording medium 35 in accordance with instructions from the CPU 31. The portable recording medium 35 is, for example, a semiconductor device (PC card or the like), a medium (flexible disk, magnetic tape, etc.) to which information is input / output by magnetic action, or a medium (optical disk) to which information is input / output by optical action. Etc.). The communication control device 36 transmits / receives data via the network in accordance with instructions from the CPU 31.

In the computer 30 configured as described above, a search request from a user is input at a user terminal, for example, and received via a network. Note that the information search apparatus of the embodiment may be realized by a single computer or a plurality of computers connected to each other. Further, the intermediary device 1, the search device 2, the temporary evaluation device 3, and the evaluation device 4 shown in FIG. 1 may be realized by executing a program, or a part thereof may be configured by hardware. Good.

(Appendix 1)
An extraction unit that extracts search elements from a plurality of search logical expressions;
A search unit for performing a database search for the search element;
Simplifying each of the plurality of search logical expressions to generate a plurality of provisional logical expressions corresponding to the plurality of search logical expressions;
A first evaluation unit that performs logical evaluation on the provisional logical expression in accordance with a search result of the search unit;
An information search apparatus comprising: a second evaluation unit that performs logical evaluation on a search logical expression corresponding to a temporary logical expression evaluated as a first evaluation value in the first evaluation unit.

(Appendix 2)
The information search device according to attachment 1, wherein
The simplification unit generates a temporary logical expression by deleting a keyword connected by an AND condition in a given search logical expression.

(Appendix 3)
The information search device according to attachment 1, wherein
The simplification unit converts the provisional logical expression defined only by an OR condition of the retrieval logical expression.

(Appendix 4)
An information search device according to appendix 1 or appendix 2,
A management unit that manages each of the plurality of provisional logical expressions with 1-bit provisional result information;
The first evaluation unit updates corresponding temporary result information managed by the management unit according to whether or not a search condition defined by the plurality of temporary logical expressions is satisfied,
The second evaluation unit refers to the management unit and performs logical evaluation only on a search logical expression corresponding to a provisional logical expression that satisfies the search condition.

(Appendix 5)
The information search device according to claim 1 or 2,
The second evaluation unit does not perform logical evaluation on the search logical expression corresponding to the temporary logical expression evaluated as the second evaluation value by the first evaluation unit, and does not perform the logical evaluation in the first evaluation unit. An information search apparatus, wherein logical evaluation is performed only for the search logical expression corresponding to when the expression is evaluated as the first evaluation value.

(Appendix 6)
An extraction unit for extracting a search element from a search logical expression;
A search unit for performing a database search for the search element;
A simplification unit for simplifying the search logical expression and generating a provisional logical expression;
A first evaluation unit that performs logical evaluation on the provisional logical expression in accordance with a search result of the search unit;
An information search apparatus comprising: a second evaluation unit that performs a logical evaluation on a search logical expression corresponding to the provisional logical expression evaluated as a first evaluation value in the first evaluation unit.

(Appendix 7)
An extraction unit realized by a computer extracts search elements from a plurality of search logical expressions,
A search unit realized by a computer performs a database search for the search element,
A simplification unit realized by a computer simplifies each of the plurality of search logical expressions to generate a plurality of temporary logical expressions corresponding to the plurality of search logical expressions,
A first evaluation unit implemented by a computer performs a logical evaluation on the provisional logical expression according to a search result of the search unit;
A second evaluation unit implemented by a computer performs a logical evaluation on a search logical expression corresponding to the temporary logical expression evaluated as the first evaluation value in the first evaluation unit;
An information search method characterized by that.

(Appendix 8)
Computer
An extraction unit that extracts search elements from a plurality of search logical expressions, a search unit that performs database search for the search elements, and a plurality of temporary logical expressions corresponding to the plurality of search logical expressions by simplifying the plurality of search logical expressions, respectively , A first evaluation unit that performs logical evaluation on the temporary logical expression according to a search result of the search unit, and a temporary logical expression that is evaluated as a first evaluation value in the first evaluation unit A second evaluation unit for performing a logical evaluation on the search logical expression corresponding to
Information retrieval program to function as

It is a figure which shows the structure of the information search device of embodiment which concerns on this invention. It is a figure explaining the method of producing | generating a temporary logic formula from a search logic formula. It is a figure explaining evaluation of a temporary logic formula. It is a figure explaining operation | movement of a temporary evaluation apparatus. It is an Example of a hit table. It is a flowchart which shows operation | movement of the information search device of embodiment. It is a figure explaining the processing amount of logic evaluation. It is a figure explaining the update of a query table and a temporary hit table. It is a block diagram of a computer that executes a program describing functions of the present invention. It is a figure which shows an example of the conventional information search device. It is a flowchart which shows operation | movement of the information search device shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mediation apparatus 2 Search apparatus 3 Temporary evaluation apparatus 4 Evaluation apparatus 11 Database 21 Query table 22 Temporary hit table

Claims (6)

An extraction unit that extracts search elements from a plurality of search logical expressions;
A search unit for performing a database search for the search element;
Simplifying each of the plurality of search logical expressions to generate a plurality of provisional logical expressions corresponding to the plurality of search logical expressions;
A first evaluation unit that performs logical evaluation on the provisional logical expression in accordance with a search result of the search unit;
An information search apparatus comprising: a second evaluation unit that performs logical evaluation on a search logical expression corresponding to a temporary logical expression evaluated as a first evaluation value in the first evaluation unit. The information search device according to claim 1,
The simplification unit converts the provisional logical expression defined only by an OR condition of the retrieval logical expression. The information search device according to claim 1 or 2,
A management unit that manages each of the plurality of provisional logical expressions with 1-bit provisional result information;
The first evaluation unit updates corresponding temporary result information managed by the management unit according to whether or not a search condition defined by the plurality of temporary logical expressions is satisfied,
The second evaluation unit refers to the management unit and performs logical evaluation only on a search logical expression corresponding to a provisional logical expression that satisfies the search condition. An extraction unit for extracting a search element from a search logical expression;
A search unit for performing a database search for the search element;
A simplification unit for simplifying the search logical expression and generating a provisional logical expression;
A first evaluation unit that performs logical evaluation on the provisional logical expression in accordance with a search result of the search unit;
An information search apparatus comprising: a second evaluation unit that performs a logical evaluation on a search logical expression corresponding to the provisional logical expression evaluated as a first evaluation value in the first evaluation unit. The information search device according to claim 1 or 2,
The second evaluation unit does not perform logical evaluation on the search logical expression corresponding to the temporary logical expression evaluated as the second evaluation value by the first evaluation unit, and does not perform the logical evaluation in the first evaluation unit. An information search apparatus, wherein logical evaluation is performed only for the search logical expression corresponding to when the expression is evaluated as the first evaluation value. Computer
An extraction unit that extracts search elements from a plurality of search logical expressions, a search unit that performs database search for the search elements, and a plurality of temporary logics corresponding to the plurality of search logical expressions by simplifying each of the plurality of search logical expressions A simplification unit that generates an expression, a first evaluation unit that performs a logical evaluation on the temporary logical expression according to a search result of the search unit, and a temporary logic that is evaluated as a first evaluation value in the first evaluation unit A second evaluator that performs a logical evaluation on the search logical expression corresponding to the expression;
Information retrieval program to function as