JPH03260869A - Data base retrieving system - Google Patents

Abstract

PURPOSE:To retrieve a data base at a high speed by retrieving a subject data group based on the character having the lowest generating frequency out of a character string to be retrieved. CONSTITUTION:A generating frequency table 2 stores the generating frequencies of characters in the retrieving subject data 1 and the head emerging place addresses of those characters. Meanwhile a following emergence table 3 stores the following emerging place addresses of the characters. A character extracting part 4 refers to a generating frequency table 2 to extract a character having the lowest generating frequency out of an inputted character string. A retrieving processing part 5 obtains successively the emerging place addresses of the characters extracted by the part 4 out of the table 2 or 3 and then compares the data set before and after the data designated by the emerging place address with the the inputted character string in order to retrieve the data including the inputted character string. Thus the data base retrieving speed is improved.

Description

[Detailed Description of the Invention] [Summary] Regarding a database search method that searches for data using character strings input by the user, the present invention allows the user to freely input words, etc. to perform a search, and to perform a faster search. For the purpose of , a character extraction unit that, when a character string to be searched is input, refers to the occurrence frequency table and extracts a character that occurs least frequently in the character string; and a character extracted by the character extraction unit. Sequentially obtain the occurrence location address from the occurrence frequency table or the next occurrence location table, compare the characters before and after the character of the search target data specified by the address with the character string, and search for data containing the character string. and a search processing unit.

[Industrial application field]

The present invention relates to a database search method for searching data using a character string input by a user.

[Conventional technology]

Storage media with large storage capacities such as CD-ROMs and optical disks have been put into practical use, and it has become possible to easily construct databases with large amounts of data such as dictionaries and modern terminology using these storage media.

The database search method is to directly search the data stored in the database (hereinafter referred to as main text data) for the word entered by the user and the word that matches, and then search for data that includes the matching word. There is a way to do it.

Another method is to provide an index in which words in text data are extracted as keywords, search the index for keywords that match the words input by the user, and search for text data indicated by the matching keywords. Search methods using this keyword include a prefix search that searches for keywords that start with the word entered by the user, a suffix search that searches for keywords that end with the entered word, and a search that searches for a keyword that ends with the entered word, and an exact match with the entered word. There is an exact match search that searches for specific keywords.

FIG. 9 is a flowchart of a conventional database search method for searching using keywords.

First, the search word input by the user is read (Fig. 9, 51). Next, the length of the read search word is determined (
S2).

First, it is determined whether it is a prefix match search (S3)
, when it is a prefix match search, the first index of the prefix match index that stores the correspondence between the first word of the phrase and the storage address in the body data based on the length of the search word, and the input and the search words found (S4).

Then, determine whether those words match (
S5).

If they match, the text data indicated by the corresponding index is read out from the CD-ROM and displayed (S6).

If the indexes do not match at this time, the next index is read (S7), and it is determined whether a search index remains depending on whether the read data is address data (3B).

If there are any indexes remaining, the process returns to step S4 and repeats the same process for the next index.

On the other hand, if it is determined in step S3 that the search is not a forward match search, the process proceeds to step S9, and it is determined whether the search is a backward match search or not. If it is a suffix match search, a similar comparison is made with the last word of the phrase and the first index of the suffix index that stores the storage address of that word in the body data (310), and then It is determined whether or not the word has been defeated (Sll).

If there is a match, the text data indicated by the searched index is read from the CD-ROM and displayed (312).
. If the indexes do not match at this time, the next index is read (S13), it is checked whether the read data is address data, and it is determined whether a search index remains (S14). If a search index remains, the process returns to step SIO and the same process is performed for the next index.

On the other hand, if it is determined in step S9 that the search is not a suffix match search, the process proceeds to step S15, where a similar comparison is made with the exact match index that stores the word and phrase and the storage address on the text data. Then, it is determined whether or not these words match (516).

If there is a match, the text data indicated by the searched index is read out from the CD-ROM and displayed (517);
If the indexes do not match at this time, the next index is read (31B), and it is checked whether the read data is address data or not, and it is determined whether a search index remains (S19). If a search index remains, the process returns to step S15 and the same process is performed for the next index.

In this way, desired text data can be searched by registering words (phrases) in the text in advance as a keyword index and comparing the search words input by the user with the index.

[Problem to be solved by the invention]

The former method of directly searching the main text data has the advantage that the user can freely select the search word, but when searching for words that match the input search word, for example, if the words in the main text data are Since it is necessary to perform a search by sequentially comparing character type positions, there is a drawback that the search takes time.

On the other hand, the latter method of searching by keyword is faster than the above method, but it has the disadvantage that the words to be searched are limited and the user cannot freely enter words to search. .

In addition, with the keyword search method, if the extracted keywords are not appropriate, it will be difficult to obtain the necessary information and it will be difficult to use, so it is necessary to be creative in extracting the keywords. For example, since it is not possible to rewrite data once written to a CD-ROM, etc., it is necessary to create simulation software for verification when extracting keywords and check whether the text data can be searched correctly using the extracted keywords. . At this time, if the verification is insufficient, the created CD-ROM will become unusable.

An object of the present invention is to enable a user to freely enter words and the like to perform a search, and to perform a faster search.

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, an occurrence frequency table 2 stores the occurrence frequency of characters in the search target data 1 and the first appearance location address where those characters appear. Further, the next appearance table 3 stores the next appearance location address of the above character.

The character extraction unit 4 refers to the occurrence frequency table 2 and extracts the character that occurs least frequently from the human-generated character string.

The search processing unit 5 sequentially obtains the appearance location address of the character extracted by the character extraction unit 4 from the occurrence frequency table 2 or the next appearance location table 3, and further searches for data before and after the data specified by the appearance location address. and the input character string to search for data that includes the human-generated character string.

Ru. Then, the characters before and after the character specified by the address are read from the search target data 1, and the read data and the character string are compared.

In this way, it is only necessary to examine the search target data for characters that occur less frequently in the human-generated character string, so the search target data can be compared sequentially. be able to.

Furthermore, since the user can freely select the character string to be searched, it becomes easier to use. Furthermore, since the search is not based on keywords, there is no need to extract keywords and, of course, there is no need to verify keywords.

[For production]

When a character string to be searched is input by the user, the character that occurs least frequently in the character string is extracted, and the storage address of that character is determined from the occurrence frequency table 2 or the next occurrence location table 3. Embodiments] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 2 shows the constituent countries of the database search device according to the database search method of the present invention.

In the figure, an input unit 11 is a keyboard for inputting words to be searched for. The display unit 12 is a display such as a CRT, and displays input words, searched text data, etc.

The processing unit 13 is a circuit that executes a database search, and is composed of a CPU 14 that reads data from a CD-ROMI 6, which will be described later, and a memory 15 that temporarily stores data read by the CPU 4.

The CD-ROMI 6 stores a text data (data registered in the database) section 17, the frequency of occurrence of characters in the text data section 17, and the address of the first appearance location of those characters in the text data section 17. A code sorting unit 18 and a next appearance table 19 storing addresses of the next appearance of the same character are provided.

FIG. 3 is a configuration diagram of the code sorting unit 18, in which characters are stored in, for example, alphabetical order, and the occurrence frequency and first appearance location address of each character are stored in correspondence with those characters. .

Next, the operation of the embodiment configured as described above will be explained with reference to the flowchart shown in FIG.

First, the code sorting section 18 is read from the CD-ROM 16 and stored in the memory (FIG. 4, 521).

Next, read the search word input by the user (S
22). Then, by referring to the code sorting unit 18, search for the least frequently occurring character among the manually generated search words,
The frequency is set in an occurrence frequency counter (not shown), and the address of the first appearance of that character is obtained (3
23), and further determines whether the occurrence frequency counter is "0" (S24).

If the value of the occurrence frequency counter is not "0", the text data indicated by the first appearance address of the code sorting section 18 is read out, and the data before and after the target character are compared with the search word (S25).

Then, it is determined whether the read data and the search word match (S26).

FIG. 5 is an explanatory diagram of the operation of obtaining the frequency of occurrence of a character from the code sorting unit 18 and the operation of reading out the corresponding text data from the first appearance location address of the character.

For example, if "Aiueo" is entered manually as a search word, the frequency of occurrence of the corresponding character is checked in the code sorting section 18, and the character that occurs least frequently in the text data is extracted from the character string. In this case, the letter "u"
Since the occurrence frequency is the lowest, the occurrence frequency "2" is set in the occurrence frequency counter. Further, the data of the first appearance location address and the addresses before and after the first appearance location address stored corresponding to the character "U" are read out. In this case, since the characters before and after the character "U" do not match the search word, a process is executed to obtain the address of the next appearance of the character "U".

Returning to FIG. 4, if the data read from the first appearance address of the main text data does not match the search word, the next appearance address of the least frequently occurring character is read from the next appearance table 19 (S27); Since one search operation has been completed through the processing up to this point, the value of the occurrence frequency counter is decremented (32B). after that,
Returning to step 324, the data of the next appearance location address read from the next appearance location table 19 and the addresses before and after it are read out and compared with the search word.

Thereafter, the processing of steps 324 to 32B described above is repeated until the value of the occurrence frequency counter becomes "0" to search for data matching the search word. If data matching the search word exists, the text data from the address specified at that time is read out and displayed on the display section (S29).
.

6 to 8 are explanatory diagrams of the search operation with reference to the next appearance location table 19.

As mentioned above, when "Aiueo" is input as a search word and the data before and after the first appearance address of the character "UJ" does not match the search word, the next appearance address of the same character is entered in the next appearance table 19. [Fig. 6].The next appearance location table 19 stores, for example, the appearance location addresses of the same character in the order of appearance, and by reading these addresses in order, the next character in the text data can be read out in order. You can search by name.

Next, as shown in FIG. 7, the data before and after the character "u" specified by the next appearance location address is read out, and it is checked whether the data matches the search word. If the two match, the text data subsequent to the matched data is read out and displayed on the display section 12, as shown in FIG.

As described above, in the above embodiment, the character with the least frequency of occurrence is extracted from the human-generated search word, and the search is performed by sequentially finding the appearance location address of that character in the text data. This makes it possible to speed up the search compared to a method in which text data is directly searched using search words manually entered by the user.

In addition, since search words are not limited to pre-extracted keywords, users can freely decide on search words.
A search method that is easier to use can be realized. Furthermore, since the search is not based on keywords, there is no problem in which it is difficult to retrieve the data that one wants to know because the extracted keywords are inappropriate.

As a result, even when producing CD-ROMs, etc., there is no need to verify keywords, making the production work easier.
CD-ROMs no longer need to be discarded due to incomplete verification.

Note that the search target data is not limited to text, but may also be combined with data such as pictures, sounds, etc. For example, if a pointer to the memory where the audio is stored is inserted between the text data, the audio can be searched along with the text. can do.

Furthermore, the present invention is not limited to the CD-ROM described in the embodiments, but can also be applied to devices using other recording media such as optical disks, and can be used for multimedia such as word processors, personal computers, and hypertext.

〔Effect of the invention〕

According to the present invention, since a target data group is searched for using characters that occur least frequently in a character string to be searched, it is possible to speed up the search. moreover,
Since the user can freely select the word to be searched, the search can be performed more easily.

[Brief explanation of drawings]

FIG. 1 is a diagram explaining the principle of the present invention. FIG. 2 is a configuration diagram of a database search device according to an embodiment. FIG. 3 is a configuration diagram of the code sorting section of FIG. 2. FIG. FIG. 5 to FIG. 8 are diagrams for explaining the search operation, and FIG. 9 is a flow chart for explaining the conventional search method.・Search target data, ・occurrence frequency table, ・next appearance location table, ・character extraction section, ・search processing section.

Claims (1)

[Claims] An occurrence frequency table (2) that stores the frequency of occurrence of a character in the search target data (1) and the address of the first appearance of the character, and the next occurrence of each character in the search target data (1). When a character string to be searched is input, the next occurrence place table (3) that stores the appearance place address and the occurrence frequency table (2) are referred to to find the character that occurs least frequently in the character string. a character extraction unit (4) that extracts the characters; and a character extraction unit (4) that sequentially obtains the appearance location address of the character extracted by the character extraction unit (4) from the occurrence frequency table (2) or the next appearance location table (3), and extracts the address. a search processing unit (
5) A database search method comprising: