KR101318234B1 - Data cache method and device for database system - Google Patents

Abstract

PURPOSE: A data cache method for a database and a device thereof are provided to process questions which are transmitted to the database, thereby offering effective and fast responses. CONSTITUTION: A question analysis unit (210) analyzes an inputted question and distinguishes the same for the inquiry or for the update. When the inputted question is for the query, a cache management unit (230) confirms the inputted question in a cache storage unit (220). When the inputted question is stored in the cache storage unit, the cache management unit extracts and outputs result information according to the inputted question. When the inputted question is not stored in the cache storage unit, the cache management unit receives/outputs the result information by calling the inputted question to a database and registers the inputted question and the result information in the cache storage unit. [Reference numerals] (210) Question analysis unit; (220) Cache storage unit; (230) Cache management unit; (240) Authentication processing unit; (250) Main control unit

Description

Data cache method and device for database system

The present invention relates to database management, and more particularly, to a data cache method and apparatus for reducing the processing load of a database system.

Nowadays, the vast amount of information is provided by the development of the Internet, etc. Most of the information data is managed and operated as a database (Database), and generally the system that manages it is called DBMS (Database Management System).

The company manages and uses a large amount of information by relying on DBMS, ranging from simple announcements that provide information to the Internet, to large-scale information such as large company information or transaction information.

In general, the following data flow occurs to provide information to the Internet.

DBMS-> WAS (web application server)-> Application program (JAVA, .Net etc.)-> Web server-> L4-> Firewall-> Internet relay device such as router-> User firewall-> User PC .

Due to the exponential growth of information provided to the Internet, the increase in the number of users, and the increase in the number of repetitions of data transmitted, the above general data flow alone has many problems in dealing with the large demands of users in a short time. And resource limitations.

So now, by building a cache server for each stage (web accelerator / CDN / browser cache, etc.) by using devices that process data to be delivered to the intermediate cache server instead of originating from the DBMS We are building a system that reduces the load on the server and allows the user to get a quick response.

The biggest problem with these cache devices, however, is that if the cached data is static data or data with relatively long update cycles, it can be effectively cached, but if the data changes frequently, or if the update cycles are unknown, then the user may have old data or It will give you incorrect information.

This is because it is difficult for the cache devices in the middle of each device to accurately determine whether the data is modified or the latest data.

As a countermeasure, if the result is sensitive data, the service is provided by excluding it from the target of the cache, and the service is applied in the form of applying the cache to the data when the data is relatively insensitive and provides the same data to many users. Is being done.

In addition, if the cache is actively managed, the developer decides the cache policy for the data when building the service page in WAS, and implements the logic for caching and updating the cache of data in a program language such as JAVA. To operate.

However, this problem occurs, too. The service provided by most corporate networks is composed of redundancy (multiple operations of server devices) for service reliability and heavy load. The system only caches effectively within individual devices, and provides uncached information for data provided by different servers (two WASs provide different results).

In order to solve this problem, complex data interworking technology called clustering must be accompanied, and the system configured in this way can cause significant performance difference depending on the developer's ability to implement cache policy. When the cache policy is established by the general developer, the cache effect is inferior or the updated data is not delivered to the user. As a result, the sensitive data is not cached and the data is simply called every time from the DBMS. Will be sent to.

In addition, static queries (queries used in the screen that are inserted into programs such as Java and served to users) are composed of many devices that can be cached by various methods, whereas dynamic queries (OLAP ( On-line Analytical Processing) or when a user sends a query directly to a DBMS or when an application connects directly to a DBMS, the cache cannot be supported because it does not go through a cache device such as a WAS or web accelerator.

Accordingly, the present invention has been made to solve the above-described problem, and to provide a data cache method and apparatus that can be located in front of a database system (DBMS), which can implement a more effective and faster response.

In addition, the present invention allows a user or an application using a database system (WAS, etc.) to go through one more security authentication process without direct access, thereby controlling more detailed and detailed user data access that the database system cannot provide. An object of the present invention is to provide a method and apparatus for caching data for a database system, which enables blocking of data leakage by an internal user.

According to an aspect of the present invention, an apparatus connected to a database system, Cache storage unit; A query analyzing unit that analyzes the input query and determines whether the query is for update or update; And checking whether the query is registered in the cache storage unit when the query is inquiring, and extracting and outputting result information according to the query stored in the cache storage unit when the query is registered. In contrast, if not registered, a data cache device including a cache manager for receiving and outputting the result information by calling the query statement to the database system and registering the query statement and the result information in the cache storage unit is provided. .

Here, the cache storage unit sequentially stores the query result information having the query statement and the result information, and table usage information having information on the order of the related query result information in table units of data managed by the database system. More can be stored.

In addition, when the query is analyzed for update by the query analyzing unit, the cache manager reflects the query statement to the database system and references the table usage information stored in the cache storage unit. The query result information recorded in the table usage information of the corresponding table is deleted from the cache storage unit.

In addition, an authentication processing unit for authenticating a user's authority according to the security level set in the query may be further included with reference to the preset query security information.

According to another aspect of the present invention, a data cache method in a device connected to a database system, the method comprising: analyzing the input query to determine whether or not for inquiry; If the query is for inquiry, checking whether the query is registered with the result information according to the query as query result information and stored in the storage means; And in accordance with a confirmation result, extracts the result information from the storage means when it is registered and outputs it. Otherwise, if not registered, the query statement is called from the database system to receive and output the result information. There is provided a data cache method for a database system comprising the step of registering the result information as new query result information and a recording medium on which a program for executing the method is recorded.

Here, the method may further include authenticating a user's authority according to the security level set in the query statement by referring to the preset query statement security information.

The new query result information may have a new order number, and the method may further include recording the new order number as table usage information of a table corresponding to the result information.

In addition, if the query is analyzed for updating, reflecting the query to the database system; And deleting the order of the query result information recorded as the table usage information of the table according to the query.

According to the present invention, it is possible to provide a data cache apparatus and a method of processing in the apparatus that provide a more effective and faster response by processing all query statements which are located at the front of the database system and flow into the database system.

In addition, according to the present invention, by authenticating the user's access authority in the unit of a query statement, it is possible to authenticate the user's access authority only by the input query statement to manage not only the simplicity of authentication processing but also the security setting or update of data. To provide convenience.

1 is a schematic diagram showing an entire system for a data cache function for a database system according to an embodiment of the present invention.
Figure 2 is a block diagram showing the configuration of a cache processing apparatus according to an embodiment of the present invention.
3 is a table illustrating query result information according to an embodiment of the present invention.
4 is an exemplary view showing table usage information according to an embodiment of the present invention.
5 is a table illustrating query statement security information according to an embodiment of the present invention.
6 is a flowchart illustrating a caching process for a database system according to an embodiment of the present invention.
7 is a flowchart illustrating a process of providing a security-enhanced cache function using security information set in another query statement in another embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout the specification and claims. The description will be omitted.

1 is a configuration diagram schematically showing an entire system for a data cache function for a database system according to an embodiment of the present invention.

Referring to FIG. 1, the entire system according to the present embodiment includes a database system 10 (DBMS), a cache processing apparatus 30, and a user 50.

The cache processing apparatus 30 according to the present embodiment is located in front of the database system 10 and processes all queries flowing into the database system 10. In other words, all queries (e.g., SQL) required from a user 50, such as a client application that requires data such as a user terminal or WAS, are not cached directly into the database system 10 but cached. It is introduced into the device (30).

The cache processing device 30 caches and stores a part of data of the database system 10, such as a proxy server, which is an Internet device, and provides the user 50 with a faster response to the query. do. In other words, the cache processing apparatus 30 does not always extract response data for a query from the database system 10, but if there is a history previously input for the query, the response data which is the query and the result information thereof. It has a cache function to store the response data to the user 50 immediately. A description of how to perform the cache function will be described later.

In this way, the cache processing device 30 is a means capable of controlling (caching or not controlling the user) in the middle of all data entering and exiting the database system 10 by using a proxy function. You get In addition, the data is processed by the cache processing unit 30, so that the query statement that performs abnormally (consuming too much time / resources) with the monitoring information such as the current query (SQL statement, etc.) and operation status / operating time, etc. It can provide a means to check and delete it.

In addition, the cache method using a proxy function is convenient for a system that is operated only by inserting a hardware cache processing device 30 without changing a software environment of the application or WAS (change of a database system connection module) or modifying a program. And effectively introduce a cache into the database system.

 In addition, since the cache processing device 30 processes all queries flowing into the database system, it may perform authentication processing for each query or user, and as a result, security to handle access rights and the like to the database system 10. Can provide functionality.

Initially, the cache processing apparatus 30 further implements a user authentication step of checking the authority to physically access the database system 10 by itself, thereby granting authority for access to the actual database system 10. It provides a more granular way.

In some cases, an application needs to access the database system 10. In general, the database system 10 is protected by a firewall to restrict access from outside the firewall. Even in the case of a web supporting system such as WAS, the system accessing the database system 10 is placed inside the firewall or only the server is opened. However, in some cases, such as a CS program, direct access to the database system 10 may occur. In this case, access to the access user is controlled using a security function as well as a proxy function of the cache processing apparatus 30. Make it manageable.

In general, the authority management of the database system 10 controls access rights in categories, tables, and views for each user. However, in a real operating environment, too much data is exposed to accessors in table units or view units.

For example, suppose you have a table that manages sales information for a specific company. If you only have access to the table (even if you have Select permission), you can access all the data in this table. Thus, for example, even if the company policy allows a user to view only sales information of his or her department, if a user with access to the table directly accesses the database system 10, the sales information of all departments can be obtained. do. Also, to prevent this, it is difficult to set the view permission for every user by creating a view for every department.

Accordingly, the cache processing apparatus 30 according to an embodiment of the present invention may provide a security policy that allows the use of a specific query statement as well as a table or view right that is an access right of the general database system 10. have. In other words, the execution authority authentication function for each query statement is implemented for a user's permission to access the database system 10. The security method of the query unit will be described in detail later with reference to related drawings.

Hereinafter, the configuration of the above-described cache processing apparatus 30 and its caching method will be described.

2 is a block diagram showing the configuration of the cache processing apparatus 30 according to an embodiment of the present invention, Figure 3 is a table illustrating the query result information according to an embodiment of the present invention, Figure 4 FIG. 5 is a diagram illustrating table usage information according to an embodiment of the present invention, and FIG. 5 is a table illustrating query statement security information according to an embodiment of the present invention.

Referring to FIG. 2, the cache processing apparatus 30 according to the present exemplary embodiment may include a query analyzing unit 210, a cache storage unit 220, a cache managing unit 230, an authentication processing unit 240, and a main controller 250. Include.

A part of data stored in the database system 10 is stored in the cache storage unit 220 according to a cache function. The stored data will be described later with reference to related drawings (FIGS. 3 to 4).

The query analyzing unit 210 analyzes a query statement, such as an SQL statement input from the user 50, to determine whether the corresponding query statement is for select or delete / update / insert, etc. It is determined whether or not the data is for updating.

In addition, the query analyzing unit 210 analyzes what table is used in the query. Analysis of the used table extracts the name of the table (TABLE) in the syntax of the [FROM] clause from the query statement.If the extracted name is not a table but a view, the table used by the view is secondary. Analyze and extract. Even if a trigger is set in the extracted table, the table to be modified is included in the target. The subquery (inline view) also performs the secondary analysis in the same form as the view and extracts the target table through the same process.

The cache manager 230 refers to the data stored in the cache storage 220, and stores the response data according to the query input from the user 50, which is an application program such as the user terminal or the WAS, as described above. 220) or extract from the database system 10 to provide to the user 50.

For example, the cache manager 230 checks whether the query is registered in the cache storage unit 220 when the input query is inquiry, and, if registered, the cache storage unit 220 when the query is registered. Extract and output the result information (ie, response data) according to the query stored in, otherwise, if not registered, the database system 10 extracts and outputs the result information using the query. Also, if the query is not registered in the cache storage unit 220, the cache manager 230 newly registers the query and the result information in the cache storage unit 220, and when the same query is input later, the database system. The result information stored in the cache storage unit 220 may be immediately provided to the user 50 without having to extract the result information from (10).

Referring to FIG. 3, which illustrates information stored in the cache storage unit 220, query result information is sequentially numbered for each input query statement and the result information.

Therefore, when the query statement is input, the cache processing apparatus 30 checks whether the corresponding query statement is registered with reference to the query result information stored in the cache storage unit 220, and if the query statement is registered, the corresponding result information. The extracted query may be provided as a response result to the user 50 who transmitted the query. For example, referring to the drawing, when a query for query [Q0001] is input from the user 50, the cache processing apparatus 30 refers to the query result information and returns the result information of [a] to the user 50. ) Can be provided.

Of course, if the input query is not registered as the query result information, the cache manager 230 extracts the query statement and the result information from the database system 10 and newly registers the empty query.

In addition, when the query input by the query analysis unit 210 is analyzed as being for update, not for query, the cache management unit 230 reflects the query to the database system 10, and also cache storage unit 220 Updates the information stored in). That is, the information according to the update query statement should be deleted from the query result information stored in the cache storage unit 220.

Referring to FIG. 5 to describe a method according to an embodiment, a history of using tables managed in the database system 10 (generally, the database manages data in table units) is stored. Information on the usage history of each table as shown in the following will be referred to as [table usage information].

For example, when the query Q0001 of the query result information according to FIG. 3 is for querying referring to tables A and C, as shown in FIG. 4, the table usage information of tables A and B is included in the order according to the corresponding query Q0001 ( 1) is recorded. Referring to the table usage information of Table A in this way, the query according to the query result information of 1, 2, 4, 7, 11, 20, 21, ... has the result information referring to Table A. it means.

Therefore, when the table A or B of the database system 10 is updated by the update query statement, the cache processing apparatus 30 refers to the table usage information, and the order according to the table usage information of the table A or B (for example, For example, the query result information of step 1, etc. is deleted.

Accordingly, since the table contents are updated, the resulting information may be changed, and thus the cache processing apparatus 30 updates the query result information stored in the cache storage unit 220. Of course, since the query result information corresponding to the updated table is deleted, the table usage information of the corresponding table is also initialized.

According to the present embodiment, by using the table usage information, query result information according to the updated table can be searched and deleted more quickly and easily.

Referring back to FIG. 2, the authentication processing unit 240 of the cache processing device 30 functions to authenticate the access right to the data of the database system 10 of the user 50.

Referring to FIG. 5 according to another embodiment, the cache processing apparatus 30 checks the security setting and security level of the input query by referring to the query statement security information in which the security level 510 for each query is set. And authentication processing accordingly. As an easy example, when the security of grade 3 is set in the query Q0003, the cache processing apparatus 30 is previously stored in the user information (self-contained or connected storage means of the device 50) inputting the query according to Q0003. If the security level of the user 50 is 3 or more, the result information according to the query Q0003 is provided to the user 50.

According to the present embodiment, security can be set in units of query statements for querying or updating specific data, so that security and setting of various data of the database system 10 can be easily performed.

In addition, the main controller 250 of the cache processor 30 controls the overall operation of each component. For example, when a query is input, the authentication processor 240 controls to process user authentication according to the query. If the authentication is successful, the query analyzer 210 analyzes the query, and the cache manager 230 performs processing of data stored in the cache storage 220 according to the analyzed query.

Although not shown, the cache processing apparatus 30 may include a communication unit for transmitting and receiving data with the user 50 through an interface unit (not shown) and a network for transmitting and receiving data with the database system 10 ( It is natural that it may further include, etc., which will be apparent to those skilled in the art and will not be described in more detail.

Hereinafter, the caching process in the cache processing apparatus 30 will be described in detail.

FIG. 6 is a flowchart illustrating a caching process for a database system 10 according to an exemplary embodiment of the present invention. FIG. 7 is a diagram illustrating security enhancement using security information set in another query statement according to another exemplary embodiment of the present invention. A flowchart illustrating a process of providing a cache function.

Referring to FIG. 6, when the query processing apparatus 30 receives a query from the user 50 (S610), the cache processing apparatus analyzes the query, and analyzes whether the query is for inquiry or for updating, and further, the query. The table recognizes a table according to the data to be used (S615). The information about the table is used to generate or update the query result information and the table usage information. Since this is described above, redundant descriptions are omitted.

The cache processor 30 determines whether the query is for inquiry or update by referring to the analysis result (S620). If the input query is for inquiry, the cache processing unit 30 refers to the query result information of the cache storage unit 220. It is determined whether the corresponding query is registered as the query result information (S630).

If the query statement input as the query result information is registered, the result information according to the query statement is extracted with reference to the query result information (S645) and provided to the user 50 who inputs the query statement (S645).

On the contrary, if the query statement is not registered as the query result information, the cache processing device 30 calls the query statement to the database system 10 to extract the result information from the database system 10 (S640). Although not shown, the cache processing apparatus 30 registers the query statement and the result information in the cache storage unit 220 as new query progress information. That is, query result information having a new order number is generated and stored in the cache storage unit 220.

 As a result of the determination in S620, when the query statement is for update rather than for inquiry, the cache processing apparatus 30 calls the query statement to the database system 10 to update the query statement so that the data according to the query statement is updated. Reflect on (S650).

Then, the query result information is updated by deleting the order of the query result information recorded in the table usage information of the table for one or more tables according to the analysis result of the update query statement (S655).

Hereinafter, as described above, the cache processing apparatus 30 provides a security function in units of query statements, and a description will be given of a processing process when the security function is set.

Referring to FIG. 7, which illustrates a process according to a security function, when the cache processing apparatus 30 receives a query (S710), the cache processing apparatus 30 is referred to the query security information as illustrated in FIG. 5. It is determined whether security is set in the query statement (S720).

If the security is not set, the process proceeds to a query statement analysis step S615 according to the cache processing process as shown in FIG.

On the contrary, when security is set for the query, the cache processing apparatus 30 checks the security level of the query and authenticates the authority of the user 50 according to the checked security level (S730).

The cache processing apparatus 30 determines whether authentication is successful as a result of the authentication process (S470). If the authentication is successful, the process proceeds to S615 as well. If authentication fails, the cache processing device 30 notifies the user of the authentication failure (S750).

According to this embodiment, after obtaining the result information by reflecting the query input from the user 50 to the database system 10, compared to the method of checking the access authority of the user 50 according to the result information, Access authority of the user 50 can be authenticated using only the inputted query, thereby providing convenience of authentication and management of security setting or update of data.

The data caching method for the database system 10 according to the present invention described above may be implemented as computer readable code on a computer readable recording medium. Computer-readable recording media include all kinds of recording media having data stored thereon that can be decrypted by a computer system. For example, it may be a ROM (Read Only Memory), a RAM (Random Access Memory), a magnetic tape, a magnetic disk, a flash memory, an optical data storage device, or the like. In addition, the computer-readable recording medium may be distributed and executed in a computer system connected to a computer network, and may be stored and executed as a code readable in a distributed manner.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that various modifications and changes may be made.

10: database system (DBMS)
30: cache processing device
50: user
210: query analysis unit
220: cache storage unit
230: cache management unit
240: authentication processing unit
250:

Claims (9)

A device connected to a database system,
A cache storage unit;
A query analyzing unit that analyzes the input query and determines whether the query is for update or update;
If the query is queryable, check whether the query is registered in the cache storage unit, and if it is registered, extract and output the result information according to the query stored in the cache storage unit according to the check result. Unless otherwise registered, a cache manager for receiving and outputting the result information by calling the query statement to the database system and registering the query statement and the result information in the cache storage unit; And
And an authentication processing unit for authenticating a user's authority according to a security level set in the query statement by referring to preset query security information.
The method according to claim 1,
The cache storage unit sequentially stores the query result and the query result information having the result information, and further stores table usage information having information about the order of the related query result information in table units of data managed by the database system. Data cache device, characterized in that.
The method according to claim 2,
When the query is analyzed for update by the query analyzer,
The cache management unit reflects the query statement to the database system, and stores the order of the query result information recorded in the table usage information of a table according to the query by referring to the table usage information stored in the cache storage unit. Data cache device, characterized in that for deleting from.
delete A data caching method in a device connected with a database system,
Authenticating a user's authority according to a security level set in an input query by referring to preset query security information;
If the authentication is successful, analyzing the query to determine whether the query is for inquiry;
If the query is for inquiry, checking whether the query is registered with the result information according to the query as query result information and stored in the storage means; And
According to the result of the check, if registered, the result information is extracted from the storage means and outputted; otherwise, if not registered, the query is called from the database system to receive and output the result information, and the query and the And registering the result information as new query result information.
delete The method according to claim 5,
The new query result information has a new order number, and further comprising the step of recording the new order number as table usage information of a table corresponding to the result information.
The method of claim 7,
If the query is analyzed for update,
Reflecting the query statement in the database system; And
And deleting the order of the query result information recorded as the table usage information of the table according to the query statement.
A recording medium readable by a digital information processing apparatus, in which a program for performing the method of any one of claims 5 and 7 is recorded.

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