JP6752547B2 - Database management method and database management system - Google Patents

Description

The present invention relates to a database management method and a database management system, and more particularly to a method and a system for managing database tables and indexes.

A database management system (DBMS) is a system for managing a database in which a huge amount of data is stored, and is indispensable in the present age when a large amount of information is constantly generated. Recognized as an important factor.

In such a DBMS, data is stored in a database in the form of a table, and here, the table means a basic structure for storing data in the database. A table is composed of one or more records. Here, the record means one row of the table. Each record is composed of one or more columns, which means a domain with a name that represents the real-world table items that make up the table, and is an attribute. Also called a field.

When a specific instruction (query) is input from the outside, such a DBMS performs functions such as data selection, insertion, update, and deletion with respect to the database by the input instruction. Here, the instruction means any request for the data stored in the table of the database, that is, what kind of operation is desired to be performed on the data, and is like SQL (structured query language). Express using various languages.

As the amount of data grows larger and larger, DBMSs generally include an index. Here, an index means a material structure that accelerates the search speed for a table in the database field, and such an index (key value, identification value) for quickly accessing a data record (tuple). Contains a pair of bookmarks.

On the other hand, if you try to delete a bookmark from some indexes, but the bookmark to be deleted fails because it is lost and does not exist in the index, the system becomes incapacitated or stopped. Or something. In such cases, the system administrator must repair the system to ensure proper operation by updating the index and / or table directly, and the system until the administrator repairs the system. Stops all work and stops. If the system goes down, losses will occur in various aspects such as manpower, time, power, and service quality, and considering the current trend that the amount of data stored in the database will become enormous, the loss due to the system down will be. , It is expected that it will grow even larger.

The above-mentioned background technology is technical information possessed by the inventor for the derivation of the present invention or acquired in the derivation process of the present invention, and is not necessarily a publicly known technology disclosed to the general public before the filing of the present invention. It is not something to do.

An embodiment of the present invention provides a database management method and a database management system. In the embodiment of the present invention, even if a part of the problem occurs in the database processing process, if it is not a fatal problem, the process is normally terminated so that the system does not become incapacitated. A database management method and a database management system are provided. The technical problem that the present embodiment poses is not limited to the technical problem as described above, and other technical problems can be inferred from the embodiment.

In one embodiment of the present invention, an identification value for acquiring an identification value of the deletion target record by searching at least one index based on the deletion instruction acquisition stage for acquiring the deletion instruction of the deletion target record and the deletion instruction. Based on the acquisition stage and the identification value of the deletion target record, the data of each item of the deletion target record acquired from the table is acquired in the deletion target record acquisition stage and the data of each item of the acquisition target record. Based on this, the index processing step includes an index processing step of deleting the bookmark of the deletion target record from each of the at least one index and a table processing stage of deleting the deletion target record from the table. Disclosed is a database management method in which the table processing step is executed and the deletion target record is deleted regardless of whether or not the deletion target record bookmark exists in all indexes.

In another embodiment of the present invention, the deletion command acquisition unit that acquires the deletion command of the record to be deleted and the identification that searches at least one index based on the deletion command and acquires the identification value of the record to be deleted. The value acquisition unit, the deletion target record acquisition unit that acquires the data of each item of the deletion target record from the table based on the identification value of the deletion target record, and the data of each item of the acquired deletion target record. Based on the above, the index processing unit includes an index processing unit that deletes the bookmark of the deletion target record from each of the at least one indexes and a table processing unit that deletes the deletion target record from the table. When deleting the bookmark of the record to be deleted, the table processing unit sets up a database management device for deleting the record to be deleted regardless of whether or not the bookmark of the record to be deleted exists in all indexes. Disclose.

Another embodiment of the present invention discloses a computer-readable recording medium in which a program for executing the above-mentioned database management method on a computer is recorded.

Other aspects, features and advantages other than those mentioned above will become apparent from the following drawings, claims and detailed description of the invention. Such general and concrete aspects are carried out using a system, method, computer program, or any combination of system, method, computer program.

The database management method and the database management system according to the embodiment of the present invention improve the operational efficiency of the database.

In the database management method and database management system according to the embodiment of the present invention, when a partial record deletion of a database is requested, bookmarks are lost in some indexes and the deletion request is not performed normally. , When it is not a fatal error, the record to be deleted can be deleted from the table normally without stopping the whole system. When the system is stopped, the consumption is large in various aspects such as human power, electric power, and time, but according to the above-described embodiment of the present invention, the consumption can be minimized.

The database management method and the database management system according to the embodiment of the present invention, when a request for inducing a specific result is received, even if there is a partial error in the database, the same as in the case where there is no error If it can be derived, the request can be normally responded to by deriving the specific result without intentionally stopping the entire system.

It is a drawing which schematically illustrated the database management system by one Embodiment. It is a block diagram which schematically illustrated the database management apparatus by one Embodiment. It is a flowchart of the database management method by one Embodiment. It is a flowchart which illustrated in detail a part of the database management method by one Embodiment. It is a drawing which illustrated an example of the table and index of the database by one Embodiment. It is a drawing which illustrated the detailed example of the table of FIG. It is a drawing which illustrated an example of the index of FIG. It is a drawing which illustrated an example of the index of FIG. It is a drawing which illustrated an example of the index of FIG.

Although the present invention can be subjected to various transformations and can have various embodiments, specific embodiments are illustrated in the drawings and will be described in detail in detail. The effects and features of the present invention, as well as the methods for achieving them, will become clear with reference to the embodiments described in detail with the drawings. However, the present invention is not limited to the embodiments disclosed below, but is embodied in various forms.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, but when the drawings are described, the same or corresponding components are designated by the same drawing reference numerals. , The duplicate explanation about it is omitted.

In the following embodiments, terms such as first and second are used for the purpose of distinguishing one component from the other components without limiting meaning. In the following embodiments, the singular representation includes multiple representations unless explicitly defined in the context. In the following embodiments, terms such as "contain" or "have" mean that the features or components described herein are present and that one or more other features. Or, the possibility that a component is added is not excluded in advance. In the drawings, the components are exaggerated or reduced in size for convenience of explanation. For example, the size and thickness of each configuration shown in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown. ..

FIG. 1 is a schematic representation of a database management system (DBMS) 1 according to an embodiment.

The database management system 1 is linked to the database 30 and performs a function of managing the database 30 in an integrated manner, such as updating or deleting the data recorded in the database 30 or adding data to the database 30. .. Referring to FIG. 1, in the database management system 1 according to the embodiment, the server 10 and the database 30 are connected to the terminal 20 via the communication network 40.

The server 10 receives various instructions from the terminal 20 and performs processing corresponding to the instructions. The instruction is also an instruction for managing the database. The server 10 is provided to provide various services to the terminal 20. Although not shown in the drawings, the server 10 according to the embodiment may further include a memory, an input / output unit, a program storage unit, a control unit, and the like. The detailed configuration included in the server 10 will be described later with reference to FIG.

The terminal 20 means a communication terminal provided with a wireless communication environment. Here, the terminal 20 is also a personal computer as shown in FIG. 1, but is not necessarily limited thereto. The terminal 20 is also a portable terminal, for example, a smartphone, and can be used without limitation as long as it is a terminal having a communication environment.

The terminal 20 can be provided with a display unit for displaying a screen, an input device for inputting data from a user, and the like.

The database 30 is a storage device that stores various data, and the data is stored in a table format. The index, which is the metadata of the table, is stored in the database 30. Hereinafter, the data stored in the table will be a record, and the record will include multi-item data. The index contains bookmarks for all records. The "bookmark" in the present specification means a set of data composed of a combination of two data, for example, (key, identification value). Here, the key is one item data of the record, and the identification value means an eigenvalue given to the record in order to identify the record. The bookmarks included in the index are sorted by the key value of each bookmark. On the other hand, a bookmark is not necessarily composed of a combination of two data. For example, a bookmark is also composed of a combination of data including a plurality of item data, such as (key 1, key 2, identification value).

Although it is illustrated in FIG. 1 that one database 30 is provided, the idea of the present invention is not limited thereto, and the number and configuration of the databases 30 are the configurations and storages of the database management system 1. It can be changed in various ways depending on the amount of data to be generated and the intended use.

The communication network 40 connects the server 10 and the terminal 20. For example, the communication network 40 provides a connection route so that packet data can be transmitted and received after the terminal 20 connects to the server 10.

FIG. 2 is a block diagram schematically showing the database management device 100 according to the embodiment. The database management device 100 illustrated in FIG. 2 is also provided in the server 10.

The database management device 100 according to the embodiment of the present invention communicates with an external device including the database 30 and manages the data stored in the database 30. For example, the data in the database 30 can be added, deleted or changed.

The database management device 100 according to an embodiment of the present invention corresponds to at least one or more processors, or may include at least one or more processors. Thereby, the database management device 100 is also driven in a form included in other hardware devices such as a microprocessor and a general-purpose computer system. The record addition processing unit 120 and the record deletion processing unit 130 can be configured by one module.

The database management device 100 illustrated in FIG. 2 illustrates only the components related to the present embodiment in order to prevent the features of the present embodiment from becoming unclear. Therefore, it can be understood by those skilled in the art in the technical field related to the present embodiment that other general-purpose components are further included in addition to the components shown in FIG. Let's do it.

Referring to FIG. 2, the database management device 100 according to one embodiment may include a communication unit 110, a record addition processing unit 120, and a record deletion processing unit 130. Hereinafter, the detailed configuration of the database management device 100 will be described with reference to FIG.

First, the communication unit 110 provides a data transmission / reception route between the components inside the database management device 100 and the external device.

When the record addition processing unit 120 receives an instruction to add a record to the database 30 from the terminal 20, the record addition processing unit 120 performs a process of adding a record to the database 30 by the instruction. The record addition processing unit 120 includes an additional instruction acquisition unit 121, a table update unit 122, and an index update unit 123.

The additional instruction acquisition unit 121 acquires an additional instruction for the record from the terminal 20. The additional instruction includes information on the record to be added to be added to the database 30.

The table update unit 122 adds the record to be added to the table of the database 30.

The index update unit 123 refers to the table to which the record to be added is added, and updates the index for the table. The update also modifies a part of the existing index, deletes the existing index, and then regenerates a new index.

When the record deletion processing unit 130 receives an instruction to delete a predetermined record stored in the database 30 from the terminal 20, the record deletion processing unit 130 performs a process of deleting the predetermined record stored in the database 30 by the instruction. The record deletion processing unit 130 includes a deletion command acquisition unit 131, an identification value acquisition unit 132, a deletion target record acquisition unit 133, an index processing unit 134, and a table processing unit 135. The record acquisition unit 133 to be deleted may include the bookmark extraction unit 1331.

The deletion command acquisition unit 131 acquires a record deletion command from the terminal 20. The delete instruction includes information on the record to be deleted among one or more records stored in the database 30. At that time, the information of the deletion target record included in the deletion instruction may include all the item data included in the deletion target record and the identification value of the deletion target record, but at least a part of the deletion target record. Only the item data may be included, or only the identification value of the record to be deleted may be included. The number of records to be deleted may be one or multiple. For example, all the records including the specific item data may be the records to be deleted. In the following, it is assumed that the deletion instruction includes one item data of the record to be deleted.

The identification value acquisition unit 132 searches at least one index based on the deletion instruction acquired by the deletion instruction acquisition unit 131, and acquires the identification value of the record to be deleted. When the deletion instruction includes the identification value information of the record to be deleted, the identification value acquisition unit 132 can also acquire the identification value information from the deletion instruction without referring to the index.

As described above, in one embodiment of the present invention, the bookmark included in the index is composed of a data pair of (key, identification value), and the key corresponds to the item data of the record. Therefore, the identification value acquisition unit 132 Can acquire the identification value of the record including the item data by searching the index for the bookmark containing the item data of the record to be deleted. The item data of the record to be deleted is also included in the deletion instruction.

The deletion target record acquisition unit 133 can acquire each item data of the deletion target record from the table based on the identification value acquired by the identification value acquisition unit 132.

The deletion target record acquisition unit 133 includes the bookmark extraction unit 1331, and the bookmark extraction unit 1331 refers to each item data of the deletion target record and extracts the bookmark corresponding to each item data. The extracted bookmark is also a data pair of (key (item data), identification value).

The index processing unit 134 deletes the bookmark of the record to be deleted from all the indexes based on each item data (or the bookmark corresponding to each item data) of the record to be deleted acquired by the record acquisition unit 133 to be deleted. can do. Such work first removes the bookmark of the record to be deleted from the index, which is the metadata of the table, before deleting the record to be deleted from the table.

When the processing of the index processing unit 134 is completed, the table processing unit 135 deletes the record to be deleted from the table. On the other hand, the table processing unit 135 deletes the deletion target record from the table at the processing stage of the index processing unit 134, regardless of whether or not the bookmark of the deletion target record exists in all the indexes. For example, even if the bookmark of the record to be deleted is lost or damaged in some indexes and there is an index that does not include the bookmark of the record to be deleted, the index processing unit 134 normally ends the index processing. As a result, even if the bookmark of the record to be deleted does not exist in some indexes and the bookmark to be deleted cannot be deleted, the table processing unit 135 can use the remaining indexes in which the bookmark of the record to be deleted exists. When the bookmark of the record to be deleted is deleted, the record to be deleted is deleted from the table.

FIG. 3 is a flowchart of a database management method according to an embodiment.

FIG. 3 is a flowchart showing an embodiment in which the database management device 100 of FIG. 2 manages the database 30. Therefore, even if the content is omitted below, the content described for the database management device 100 described in FIG. 2 is also applied to the database management method according to the embodiment of FIG.

Referring to FIG. 3, in step 31, the additional instruction acquisition unit 121 or the deletion instruction acquisition unit 131 of FIG. 2 acquires an instruction for database management, and proceeds to step 32.

If the instruction acquired in step 31 is a record addition instruction, the process proceeds from stage 32 to stage 311. If the instruction is a record deletion instruction, the process proceeds from stage 32 to stage 321.

First, when proceeding to stage 311, in stage 311 the table update unit 122 of FIG. 2 adds the record to be added to the table and updates the table.

At step 312, the index update unit 123 refers to the table updated in step 311 and updates the index of the table. When step 312 is complete, the record addition process is complete.

When proceeding from step 32 to step 321, in step 321 the identification value acquisition unit 132 of FIG. 2 searches at least one index based on the deletion instruction acquired in step 31, and obtains the identification key of the record to be deleted. Acquire.

In step 322, the deletion target record acquisition unit 133 acquires each item data of the deletion target record from the table based on the identification key of the deletion target record.

At step 323, the bookmark extraction unit 1331 extracts bookmarks corresponding to each item of the acquired record to be deleted.

In step 324, the index processing unit 134 deletes the bookmark of the record to be deleted from each of at least one index based on the item data acquired in step 322. Alternatively, at step 324, the index processing unit 134 deletes the bookmark of the record to be deleted from each of at least one index based on the bookmark extracted in step 323. For example, the bookmark extraction unit 1331 refers to the data of the predetermined item of the record to be deleted, and deletes the bookmark of the record to be deleted from the index in which the bookmarks are arranged based on the predetermined item. Alternatively, the bookmark extraction unit 1331 refers to the bookmark corresponding to the predetermined item of the record to be deleted, and deletes the bookmark of the record to be deleted from the index in which the bookmarks are arranged based on the predetermined item. Step 324 is iteratively performed and performed on all indexes stored corresponding to the table.

At step 325, the table processing unit 135 deletes the record to be deleted from the table. On the other hand, in step 325, the table processing unit 135 deletes the record to be deleted from the table regardless of whether or not the bookmark of the record to be deleted exists in all the indexes before the step 324 is executed. For example, even if the bookmark deletion of the record to be deleted fails in some indexes in the stage 324, the table processing unit 135 normally deletes the record to be deleted in the stage 325. Here, the meaning of failing to delete the bookmark is that the bookmark of the record to be deleted is normally included in the index before the stage 324 is executed, and the bookmark is deleted normally in the stage 324. Including all cases. For example, if the bookmark of the record to be deleted does not exist in some indexes and the bookmark of the record to be deleted does not exist, or because the bookmark of the record to be deleted does not exist in some indexes. Including the case where the bookmark of the record to be deleted is artificially added and then the added bookmark is further deleted.

At step 326, the table processing unit 135 can output a completion message notifying that the deletion of the record to be deleted is completed from the table. The completion message is transmitted to the terminal 20.

On the other hand, in the above, the example in which the instruction acquired in the stage 31 is a delete instruction or an additional instruction has been described, but the instruction acquired in the stage 31 is also a record change instruction. Since the change instruction is the same as the work of adding a new record after deleting the existing record, the change instruction acquired in step 31 is divided into a delete instruction and an additional instruction. When the instruction acquired in the stage 31 is a change instruction of the record to be changed, first, the record to be changed is deleted from the database 30 through the stage 321 and the following stages, and then the stage 311 and the following steps are performed. The record to be changed can be added to the database 30 through the steps.

On the other hand, the processing related to the change instruction is not limited to the above method. For example, when processing a change command, the step of deleting bookmarks one by one from the index may be omitted. For example, a record stored in a table can be overwritten with a new record to update the table, and then the index can be updated for the updated table. In addition, for quick processing, it is possible to update only the index for changed items for existing records.

On the other hand, in the process of recording and reading data in the database 30, the database management device 100 according to the embodiment can utilize the internal memory provided inside the database management device 100 to increase the data processing speed.

FIG. 4 is a flowchart illustrating a part of the database management method according to the embodiment in detail.

In detail, FIG. 4 is a flowchart illustrating in detail an example of step 324 in the database management method of FIG.

Referring to FIG. 4, in step 41, the index processing unit 134 refers to the item (or the extracted bookmark) of the record to be deleted, and whether or not each index includes the bookmark of the record to be deleted. Confirm that. If the bookmark of the record to be deleted is included in the index, the process proceeds to step 411 to delete the bookmark of the record to be deleted from the index. On the other hand, if the bookmark of the record to be deleted is not included in the index, the process proceeds to step 421.

In step 421, the index processing unit 134 adds a bookmark of the record to be deleted to the index, deletes the added bookmark in step 422, and outputs an error log in step 423. When outputting the error log in step 423, the index processing unit 134 can set the state of the database management system 1 to the active (valid) state. Even if the state of the database management system 1 is changed to the invalid state by the index that does not include the bookmark of the record to be deleted, the database management is performed by forcibly changing it to the active state. This is to operate the system 1 normally.

On the other hand, steps 421 and 422 may be omitted. In other words, when an index that does not include the bookmark of the record to be deleted is confirmed in step 41, the index processing unit 134 omits the bookmark deletion process for the index, and in step 423, only the error log. Is output, the indexing process can be terminated and the process can proceed to step 325 in FIG.

The indexing method illustrated in FIG. 4 is iteratively performed for every index that exists corresponding to the table.

FIG. 5 illustrates an example of a database table and index according to one embodiment.

Referring to FIG. 5, the database 30 includes a table 51 in which various data are stored and an index 52 which is the metadata of the table 51.

Table 51 includes one or more records R1, ..., Rn, and each record contains one or more item data. For example, in the case of a database in which bulletin boards related to a predetermined bulletin board are stored, a table means a set of bulletin boards, a record means each bulletin board, and an item is a bulletin board identifier and a bulletin board creator. , Means the area where the number of hits etc. is saved. As another example, when the user account is a stored database, the table means a set of user accounts, the record means each user account, and the item is the identifier of the user account, ID (identification). , Username, age, gender, contacts, etc. are stored in the area.

The index 52 is a material structure provided for increasing the speed of operation with respect to the table 51. For example, the index 52 has a structure in which bookmarks of records included in the table 51 are arranged with respect to a predetermined item. ..

Several indexes 52 are provided. For example, the index 52 is provided as many as the number of items in the record. Each index 52 can arrange and store bookmarks of records included in the table 51 based on items different from each other.

With reference to FIG. 5, the first index 521 in which the record bookmarks B1R1, ..., B1Rn are arranged based on the first item, and the record bookmarks B2R1, ..., B2Rn are arranged based on the second item. It can be seen that the third index 523 in which the bookmarks B3R1, ..., B3Rn of the record are arranged based on the second index 522 and the third item is exemplified.

On the other hand, the table 51 is stored in the user data area of the database 30, and the index 52 is stored in the metadata area of the database 30, but is not necessarily limited thereto.

FIG. 6 illustrates a detailed example of the table 51 of FIG.

Referring to FIG. 6, table 51 includes a plurality of records. Although FIG. 6 shows the first record R1, the second record R2, and the third record R3, the table 51 may include more records or even fewer records.

In the example of FIG. 6, the database stores user accounts. In this example, the table 51 stores the user account, the record corresponds to the user account, and the items are detailed information included in the user account, for example, item 1 is a name, item 2 is a gender, and item 3. Is illustrated to correspond to age.

On the other hand, the detailed item data of the record shown in FIG. 6 is an example, and the embodiment of the present invention is not limited thereto. The record may contain more items and may contain fewer items.

7A to 7C show an example of the index 52 of FIG.

In detail, FIG. 7A illustrates an example of a first index 521, FIG. 7B illustrates an example of a second index 522, and FIG. 7C illustrates an example of a third index 523. The first index 521, the second index 522, and the third index 523 arrange the bookmarks of the records contained in the table 51.

The key of the bookmark included in the first index 521 is item 1, that is, in the case of this example, the name data, and the bookmarks included in the first index 521 are arranged in the order of names. The key of the bookmark included in the second index 522 is item 2, that is, in the case of this example, the gender data, and the bookmarks included in the second index 522 are arranged in the order of gender. The key of the bookmark included in the third index 523 is item 3, that is, in the case of this example, the age data, and the bookmarks included in the third index 523 are arranged in order of age.

Hereinafter, a database management method according to an embodiment will be described with reference to FIGS. 6, 7A, 7B, and 7C.

First, the deletion command acquisition unit 131 of FIG. 2 acquires a deletion command from the user. The deletion order is acquired based on a predetermined item. For example, the user may transmit the deletion instruction to the server 10, and the deletion instruction may include predetermined item data. For example, the content of the deletion order is to delete the account of "Kim Chorus". In the following, assuming this case, embodiments of the present invention will be described exemplary.

If the above-mentioned deletion command is acquired, the identification value acquisition unit 132 of FIG. 2 refers to the first index based on the deletion instruction and acquires the identification value of "Kim Chors". In detail, the identification value of the bookmark including the item data "Kim Chorus" is acquired. With reference to FIG. 7A, the identification value of "gold chorus" is 3.

Next, the deletion target record acquisition unit 133 of FIG. 2 acquires the record R3 corresponding to the identification value of “Kim Chors”, that is, the deletion target record. The record acquisition unit 133 to be deleted can extract bookmarks corresponding to each item (Kim Chors, man, 35, ...) Of the record R3. The extracted bookmarks include, for example, (Kim Chorus, 3), (Man, 3) and (35, 3).

Next, the index processing unit 134 of FIG. 2 refers to the item data of the record R3 (or refers to the extracted bookmark), and deletes the bookmark of the record R3 to be deleted from all the indexes. For example, the bookmark B1R3 of the record R3 to be deleted is deleted from the first index 521 shown in FIG. 7A, and the bookmark B2R3 of the record R3 to be deleted is deleted from the second index 522 shown in FIG. 7B. The bookmark B3R3 of the record R3 to be deleted is deleted from the third index 523 illustrated in.

However, referring to FIG. 7C, it can be seen that the bookmark of the record R3 to be deleted does not exist. In fact, in the process of operating the database 30, bookmarks of some indexes may be lost or damaged, and the third index 523 of FIG. 7C illustrates such an example.

In the case of one embodiment of the present invention, as in the example of FIG. 7C, even if the bookmark to be deleted is not in the index, the index processing unit 134 of FIG. 2 does not stop the system, and the deletion is performed normally. Then proceed to the next stage. Even if the bookmark to be deleted is not in the index, the following processing can be performed to recognize that the deletion was performed normally.

The first method is to add the bookmark to be deleted to the index. The index processing unit 134 can delete the added bookmark. In that case, since the bookmark deletion process of the record to be added is actually executed from all the indexes, the indexes are processed normally.

The second method is when there is no bookmark to be deleted in the index and a problem occurs in the operation of the database management system 1 in the data processing process, for example, when the state of the database management system 1 is changed to the inactive state. The index processing unit 134 forcibly changes the state of the database management system 1 to the active state. According to this, even if the bookmark deletion process of the record to be added is not actually performed in some indexes, the database management system 1 cannot recognize the error, so that the index is processed normally. ..

The above-mentioned method is an example of a detailed method for normally terminating data processing without causing an error when the bookmark to be deleted is not in the index, and a method other than the above-mentioned example is used in the present embodiment. It applies.

On the other hand, in the process of referring to the deletion instruction acquired from the user and acquiring the identification value of the record to be deleted from the specific index, the bookmark of the record to be deleted is lost in the specific index, so that the record to be deleted is deleted. It may not be possible to obtain an identification value.

For example, from the example of FIGS. 6 to 7C, when a deletion command to delete a user account having an age of 35 is acquired, data of 35 from the third index 523, which is an index corresponding to the age item, is obtained. Search for bookmarks that contain as a key. However, in the case of the third index 523 illustrated in FIG. 7C, the bookmark containing 35 as a key is lost and does not exist. In such a case, the database management device 100 according to the embodiment of the present invention does not substantially perform the deletion process, but can temporarily terminate the response to the deletion command normally.

As a result, the record to be deleted that the user deletes (in the above example, the user account of age 35, that is, R3) still exists in the table, but it is different from leaving an error log or the like. As a matter of fact, the database management device 100 can normally end the response to the deletion command. As a result, the server 10 operates normally without stopping.

The bookmark deletion process of the record to be deleted is completed from all the indexes including the first index 521, the second index 522, and the third index 523 (even if the bookmark is deleted or the bookmark is not deleted). (Including the case where the error is ignored), the table processing unit 135 in FIG. 2 deletes the record R3 from the table 51 in FIG. At that time, the table processing unit 135 does not care about the table even if the bookmark of the record to be deleted is not deleted because the bookmark of the record to be deleted does not exist in some indexes. Delete record R3 from 51.

Assuming that all indexes include bookmarks of records to be deleted and some indexes do not include bookmarks of records to be deleted, according to one embodiment of the present invention. The database 30 after the deletion process of the record to be deleted is performed is the same.

Traditionally, for some indexes, if a bookmark is lost and the bookmark to be deleted fails to be deleted, the system is disabled or stopped. In such cases, the system administrator must repair the system to ensure proper operation by updating the index and / or table directly, until the administrator repairs the system. The system stopped and stopped all work.

However, according to the above-described embodiment of the present invention, when a deletion request for a part of a record in the database is requested, a fatal error occurs even if the bookmark is lost in some indexes and the deletion request is not performed normally. If not, you can successfully delete the records to be deleted from the table without shutting down the entire system. When the system is stopped, the consumption is large in various aspects such as human power, time, power, and service quality, but according to the above-described embodiment of the present invention, the consumption can be minimized.

According to the above-described embodiment of the present invention, when a request for inducing a specific result is received, even if there is a partial error in the database, the specific result can be derived in the same manner as when there is no error. If there is, the request can be normally responded to by deriving the specific result without intentionally stopping the entire system. However, leave an error log and refer to it for database management and inspection. On the other hand, the database management method shown in FIGS. 3 and 4 can be realized by a program executed by a computer, and is realized by a general-purpose digital computer that operates the program by using a recording medium that can be read by the computer. Will be done. The computer-readable recording medium includes a magnetic recording medium (for example, ROM (read only memory), floppy disk (registered trademark), hard disk, etc.), an optical reading medium (for example, CD (compact disc) -ROM, etc.). Includes recording media such as DVDs (digital versatile discs).

The present invention has been described above, focusing on its preferred embodiments. Those skilled in the art to which the invention belongs will appreciate that the invention is embodied in a modified form to the extent that it does not deviate from the essential properties of the invention. Therefore, the disclosed embodiments must be considered from a descriptive point of view, not from a limiting point of view. Since the scope of the present invention is shown in the claims rather than the above description, all differences within the equivalent scope must be construed as included in the present invention. is there.

The database management method and database management system of the present invention can be effectively applied to, for example, information processing-related technical fields.

1 Database management system 10 Server 20 Terminal 30 Database 40 Communication network 51 Table 52 Index 521 1st index 522 2nd index 523 3rd index 100 Database management device 110 Communication unit 120 Record addition unit 130 Record deletion unit 121 Additional instruction acquisition unit 122 Table update unit 123 Index update unit 131 Delete command acquisition unit 132 Identification value acquisition unit 133 Delete target record acquisition unit 1331 Bookmark extraction unit 134 Index processing unit 135 Table processing unit R1 1st record R2 2nd record R3 3rd record

Claims (9)

The deletion command acquisition stage to acquire the deletion command of the record to be deleted, and
Based on the deletion instruction, the identification value acquisition step of searching the index and acquiring the identification value of the deletion target record, and
The deletion target record acquisition stage for acquiring the data of each item of the deletion target record from the table based on the identification value of the deletion target record, and the deletion target record acquisition stage.
An index processing step of deleting a bookmark of the deletion target record from each of the at least one index based on the acquired data of each item of the deletion target record, and
A table processing step of deleting the record to be deleted from the table is included.
In the index processing stage, when an index that does not include the bookmark of the record to be deleted is confirmed, a method of adding the bookmark of the record to be deleted to the index and then deleting the added bookmark , and A database management method in which the index is processed by any one of the methods of omitting bookmark deletion. The index processing step is
The database management method according to claim 1, wherein when an index that does not include a bookmark of the record to be deleted is confirmed, an error log is output and the process proceeds to the table processing stage. The deletion target record acquisition stage is
It further includes a bookmark extraction stage that extracts bookmarks corresponding to each of the acquired items of the record to be deleted.
The database management method according to claim 1, wherein the index processing step confirms whether or not the bookmark is included in the index of the item corresponding to the extracted bookmark. The additional instruction acquisition stage to acquire the additional instruction to add the record to be added to the database, and
In the table update stage where the record to be added is added to the table,
The database management method according to claim 1 or 2, further comprising an index update step of referring to the table to which the addition target record has been added and updating the index of the table. The deletion command acquisition unit that acquires the deletion command of the record to be deleted,
An identification value acquisition unit that searches at least one index based on the deletion instruction and acquires the identification value of the record to be deleted.
A deletion target record acquisition unit that acquires data of each item of the deletion target record from the table based on the identification value of the deletion target record, and a deletion target record acquisition unit.
An index processing unit that deletes a bookmark of the deletion target record from each of the at least one index based on the acquired data of each item of the deletion target record.
Includes a table processing unit that deletes the record to be deleted from the table.
The indexing unit, if the index does not contain the bookmark of the deleted record is confirmed, the index, after adding a bookmark of the deleted record, a method of deleting the added bookmark and, A database management device that processes the index by any one of the methods of omitting bookmark deletion. The index processing unit
The database management device according to claim 5, wherein an error log is output when an index that does not include a bookmark of the record to be deleted is confirmed. The record acquisition unit to be deleted is
It further includes a bookmark extraction unit that extracts bookmarks corresponding to each of the acquired items of the record to be deleted.
The database management device according to claim 5, wherein the index processing unit confirms whether or not the bookmark is included in the index of the extracted item corresponding to the bookmark. The additional instruction acquisition unit that acquires additional instructions for adding the record to be added to the database,
A table update unit that adds the record to be added to the table,
The database management device according to claim 5 or 6, further comprising an index update unit that refers to the table to which the addition target record is added and updates the index of the table. A computer program for executing the method according to any one of claims 1 to 4 on a computer.

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