KR20210060930A - Column-Oriented Database Management System - Google Patents

Abstract

The present application relates to a column-based database management device which may comprise: a data storage part wherein a received monitoring information and meta information corresponding to the monitoring information from the measuring devices that measured a monitoring target is stored based on a column and managed; and a control part that provides an interface directly accessible to the data storage part in response to a request for access to the monitoring information. Therefore, the present invention is capable of providing an improved performance in terms of efficiency in memory usage, input/output speed, scalability, and flexibility.

Description

Column-oriented database management system {Column-Oriented Database Management System}

The present application relates to a database management device that stores and manages monitoring data collected from the power system. In particular, a column is used as a minimum constituent unit, thereby increasing memory efficiency and securing flexibility according to structural changes. It relates to a database management device based on.

The EMS (Energy Management System) is the highest level system in the power system and is in charge of the overall power supply and demand and operation of the system. As can be seen in the case of global power outages abroad, its importance is increasing day by day. The application programs of the power system operation system periodically perform power generation planning functions such as automatic power generation control and economic dispatch for system operation, and system analysis functions such as state estimation, current analysis, failure analysis, and presumed accident analysis. Is provided to the operator.

The database of the currently operating Korean power system operation system is composed of RTDB (Realtime Database, Memory DB) not RDB (Relation Database) based on ACM (application common model) model. In other words, only RTDB (Realtime Database) optimized to accommodate large amounts of data processing acquired from SCADA (Supervisory Control and Data Acquisition System) and large amount of input/output data processed by EMS application program execution can accommodate such a case. However, in the case of the conventional RTDB, it is difficult to flexibly cope with the changing technology trend due to the static configuration.

The present application intends to provide a column-based database management device that can increase memory efficiency and secure flexibility according to structural changes by using a column as a minimum unit of construction.

The present application is intended to provide a column-based database management device that does not require recompilation of an application program or restart of the database when adding or changing a database by removing the dependency with the linked application program.

The column-based database management apparatus according to an embodiment of the present invention is connected to an EMS (Energy Management System) and collects monitoring information from monitoring targets included in an electric power system. It relates to a database management system (DBMS) that stores and manages, and includes monitoring information received from measurement devices measuring the monitoring target and meta information corresponding to the monitoring information, based on a column. A data storage unit that stores and manages; And a control unit providing an interface directly accessible to the data storage unit in response to a request for access to the monitoring information.

Here, the data storage unit distinguishes the monitoring information or meta information for each class, forms columns corresponding to items included in each class, and then, according to the input of the monitoring information or meta information, the You can store the rows by filling them sequentially.

Here, the meta information may include storage location information of the monitoring information for accessing the monitoring information.

Here, the control unit, upon receiving a request for the monitoring information from the power system operating system, returns meta-information including storage location information of the monitoring information, so that the power system operating system directly accesses the monitoring information. Interface can be provided.

Here, when the column corresponding to the monitoring data is added or changed, the controller may update meta information corresponding to the storage location information.

In addition, the solution to the above-described problem does not enumerate all the features of the present invention. Various features of the present invention and advantages and effects thereof may be understood in more detail with reference to the following specific embodiments.

According to the column-based database management apparatus according to an embodiment of the present invention, since columns are stored as a minimum configuration unit, improved performance in terms of memory usage efficiency, input/output speed, scalability and flexibility can be provided. have.

According to the column-based database management apparatus according to an embodiment of the present invention, it is possible to remove the dependency with the application program of the interlocked power system operating system, so the structure of the database without recompiling the application program or restarting the database. It is possible to perform changes and the like.

However, the effects that can be achieved by the column-based database management apparatus according to the embodiments of the present invention are not limited to those mentioned above, and other effects not mentioned are the technical fields to which the present invention belongs from the following description. It will be able to be clearly understood by those of ordinary skill.

1 is a block diagram showing a power system system according to an embodiment of the present invention.
2 is a block diagram showing a database management apparatus according to an embodiment of the present invention.
3 is a schematic diagram showing a row-based database structure and a column-based database structure.
4 is a schematic diagram showing the structure of a row-based database and data storage in a column-based database structure.
5 is a schematic diagram showing a case where an item is added in a row-based database.
6 is a schematic diagram showing a case where an item is added in a column-based database.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the present invention. However, in describing a preferred embodiment of the present invention in detail, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, the same reference numerals are used throughout the drawings for parts having similar functions and functions.

In addition, throughout the specification, when a part is said to be'connected' with another part, it is not only'directly connected', but also'indirectly connected' with another element in the middle. Includes. In addition, "including" a certain component means that other components may be further included rather than excluding other components unless otherwise stated. In addition, terms such as "~ unit" and "module" described in the specification mean a unit that processes at least one function or operation, which may be implemented as hardware or software, or as a combination of hardware and software.

1 is a block diagram showing a power system system according to an embodiment of the present invention.

Referring to FIG. 1, a power system system according to an embodiment of the present invention includes an electric power system (1), a measuring device 10, a database management device (DBMS: Database Management System, 100), and a power system operation. It may include a system (EMS: Energy Management System, 200).

Hereinafter, a power system system according to an embodiment of the present invention will be described with reference to FIG. 1.

The measuring device 10 can acquire monitoring information about the state of a power plant, a transmission/distribution system, a consumer's load system, and the like constituting the power system 1. That is, the measuring device 10 provides various monitoring information from the power system 1 to perform functions such as quick and accurate monitoring of the power system 1, optimized automatic power generation control, and power system analysis. You can get them. For example, the measurement device 10 directly acquires data from a remote terminal unit (RTU) installed in a generator or substation, or SCADA (Supervisory Control and Data Acquisition System) or external Data can be linked and acquired from the system.

The database management device 100 may receive the monitoring information collected by the measurement device 10, and manage and operate the received monitoring information to suit each purpose. That is, the database management device 100 may receive and store real-time monitoring information indicating the current state of the power system from the measurement device 10, and according to the embodiment, the system application program of the power system operation system 200 and the It is also possible to store power system facility modeling, power system connection relationship modeling, etc. to support generator control applications. Here, the database management apparatus 100 may be linked with the power system operating system 200 through an application program, and may provide monitoring information according to the request of the power system operating system 200. In addition, depending on the embodiment, after storing and backing up all data related to power system monitoring and control collected and transmitted from the power system operation system 200, it can be provided upon request. Can be provided as

The power system operation system 200 may receive monitoring information from the database management device 100, and perform various management and control for the operation of the power system 1 by using the received monitoring information. Specifically, it can perform power generation planning functions such as automatic power generation control and economic dispatch, and system analysis functions such as condition estimation, current analysis, failure analysis, and presumed accident analysis. Thereafter, the execution result may be stored in the database management apparatus 100 again.

Here, since each power generation plan and system analysis function performed by the power system operation system 200 must be completed within a few seconds to a few minutes, fast processing performance for input/output of data such as monitoring information is required. Therefore, in the conventional database management apparatus, it is implemented to be stored on a row basis in the same way as the structure of the C language, so as to ensure a fast input/output processing speed of data. However, in the case of a row-based database, memory usage is inefficient, and due to a static structure, addition, change, or deletion of the database during service is impossible. When applying changes, the source code is recompiled and the database is restarted. There were also disadvantages such as the need for a back.

In order to solve this problem, the database management apparatus 100 according to an embodiment of the present invention has been implemented to store data such as monitoring information based on a column, through which memory usage efficiency, input/output speed, and expansion It is possible to provide improved performance in terms of performance and flexibility. Hereinafter, a database management apparatus 100 according to an embodiment of the present invention will be described.

2 is a block diagram showing a database management apparatus according to an embodiment of the present invention. Referring to FIG. 2, the database management apparatus 100 according to an embodiment of the present invention may include a data storage unit 110 and a control unit 120.

The data storage unit 110 stores and manages the monitoring information received from the measurement devices 10 measuring the monitoring target and meta information corresponding to the monitoring information in a database (not shown) based on a column. I can. That is, conventionally, the structure was stored on a row basis like the structure of the C language, but in this case, the database can be implemented by storing on a column basis. Specifically, the data storage unit 110 can distinguish monitoring information or meta information for each class or table, and after forming columns corresponding to items included in each class, input monitoring Information or meta-information can be stored in a manner that sequentially fills each column.

Referring to Fig. 3(a), if information corresponding to a class such as a generator code, region, generator name, energy source, generation amount, etc., has been continuously input and stored in the row direction, data according to an embodiment of the present invention In the case of the storage unit 110, as shown in Fig. 3(b), after classifying each class, it is possible to sequentially store data in a column direction for each class. Here, since data is stored for each class, for example, in the case of extracting the entire "generator code", it is possible to extract simultaneously in units of columns. That is, it is possible to perform data input/output more conveniently and quickly.

On the other hand, in the case of row-based storage, the structure S1 can be first set as follows, and then the structure can be stored in units of each set structure S1. Here, it is assumed that 6 structures S1 are stored.

struct S1{

char a;

int b;

double c;

}

At this time, "char", "int", and "double" each correspond to a command for declaring a variable in the C language, so 1 byte is allocated to a declared as char, and 4 bytes are allocated to b declared as int. Each of 8 bytes can be allocated to c declared as double. Here, since b is set to have an offset of 3 bytes between a and, as shown in Fig. 4(a), six structures can be stored. However, due to the offset between a and b, 18 bytes out of 96 bytes of total memory usage are not actually used (hatched area).

On the other hand, in the case of the data storage unit 110 according to an embodiment of the present invention, since it is stored on a column basis, column a is set to char type, column b is set to int type, and column c is set to double type. Each can be set. That is, since the column a in which a is stored is set to a char type, each 1 byte is allocated, and since column b is set to an int type, 4 bytes are each allocated, and column c is set to a double type, so each 8 bytes may be set. Accordingly, as shown in Fig. 4(b), six records including three items a, b, and c for one class may be stored on a column basis. In this case, since only 2 bytes of the total memory usage amount of 80 bytes remain without being actually used, a relatively efficient memory use is possible.

That is, when comparing FIGS. 4(a) and 4(b), it can be seen that the column-based structure uses about 16 bytes less in terms of memory usage than the row (C-structure)-based structure. Here, the number of input records is only 6, but in the case of the database management apparatus 100 operating in the actual power system 1, a large amount of system facility information may be stored. Therefore, it is possible to save a considerable amount of memory by using the data storage unit 110 implemented on a column basis. In addition, since more and more monitoring information is being added to the database management apparatus 100, if the data storage unit 110 of the present invention is used, it is possible to implement more efficient memory use despite the limited memory capacity of the operating system.

Meanwhile, since the data storage unit 110 according to an embodiment of the present invention stores data on a column basis, even if an additional item or the like is further included in the class, the previously stored memory structure may not be changed.

In general, when a new item is added to the structure of the C language, the memory structure of FIG. 5(a) may be changed to the memory structure of FIG. 5(b). That is, initially char a, int c, and double b may be serially and consecutively allocated as shown in Fig. 5(a). However, in the case where int d is added, 4 bytes corresponding to int and 4 bytes according to the memory allocation rule are additionally added, and as shown in FIG. 5(b), it may be shifted to the right by 8 bytes. As described above, if the memory structure is changed as a whole, it cannot be applied while the database is operating, and it is necessary to recompile the application program and restart the database according to the addition of items. However, since the power system operating system 200 is very important in performance stability and data reliability along with fast execution speed, in the case of restarting the database to apply changes, the stability and reliability of the system analysis application program are guaranteed. It may cause problems such as hindering.

On the other hand, since the data storage unit 110 according to an embodiment of the present invention stores data on a column basis, in the case where char d is further included in FIG. 4(b), the column d is simply added to correspond to d. It is possible to enter column d. That is, as shown in FIG. 6, column d may be added, and it can be seen that the memory address of an already allocated field is not changed despite the addition of column d. Therefore, according to the data storage unit 110 according to an embodiment of the present invention, even when an addition or change to an item in a class occurs, recompilation of the application program of the power system operating system 200 or a database There is no need to restart the management device 100, and it is possible to ensure continuity and reliability of work.

The control unit 120 may provide an interface directly accessible to the data storage unit 110 in response to a request for access to the monitoring information. That is, since the database management apparatus 100 according to an embodiment of the present invention is implemented so that class information of the database is not bound when compiling an application program, the application program has a memory address for accessing each monitoring information, etc. Not equipped. Accordingly, the control unit 120 may provide a separate interface so that the application program can access monitoring information and the like through the database management apparatus 100.

Specifically, the data storage unit 110 stores meta information on the monitoring information, and the meta information includes a class, column data type, size, etc. for each monitoring information, as well as storage location information in which the monitoring information is stored. Included. Accordingly, the control unit 120 may implement the application program to access each monitoring information by using the meta information.

That is, the application program may first access the database management device 100 to inquire meta information corresponding to the storage location information in which the monitoring information is stored. In this case, the control unit 120 may provide the meta information to the application program. I can. Thereafter, the application program can obtain the storage location information on the memory in which the monitoring information is stored from the meta information, and use the memory storage location information to inquire and change the monitoring information.

Conventionally, class information in a database was bound at the time of compiling an application program. In this case, since the linkage between the application program and the database is statically connected, if table and column information of the database is changed, all related application programs must be recompiled. That is, since the entire memory address stored and managed by the database is changed, the address of the class referenced by the application program is changed. For example, assuming that the program A refers to the table T1 and the program B refers to the table T2, when a field is added to T1, and there is no dependency between memory, the program A uses T1. You only need to recompile. However, in the case of a row-based database, memory is serially stored, so when a row is added, the entire memory address is shifted, so both A and B must be compiled, and the database must be restarted.

On the other hand, since the control unit 120 according to an embodiment of the present invention excludes the dependency between the database and the application program, it is not necessary to recompile the application program every time a column of the database is added or changed. In addition, in the case of a column-based database, memory shift due to addition does not occur even when a column is added or changed, so the existing memory address can be used as it is, and the memory address information for the added column is added to the metadata. In this way, flexibility and scalability can be guaranteed. In this case, the control unit 120 may update meta information corresponding to the storage location information, so that a column corresponding to the monitoring data may reflect the addition or change.

The present invention is not limited by the above-described embodiments and the accompanying drawings. It will be apparent to those of ordinary skill in the art to which the present invention pertains, that components according to the present invention can be substituted, modified, and changed within the scope of the technical spirit of the present invention.

1: power system 10: measuring device
100: database management device 110: data storage unit
120: control unit 200: power system operation system

Claims (5)

In a database management system (DBMS: Database Management System) that is linked with the power system operation system (EMS) and stores and manages monitoring information collected from the monitoring targets included in the electric power system. ,
A data storage unit for storing and managing monitoring information received from measurement devices measuring the monitoring target and meta information corresponding to the monitoring information on a column basis; And
In response to a request for access to the monitoring information, a column-based database management apparatus comprising a control unit providing an interface directly accessible to the data storage unit.
The method of claim 1, wherein the data storage unit
The monitoring information or meta information is classified for each class, columns corresponding to items included in each class are formed, and then the columns are sequentially filled and stored according to the input of the monitoring information or meta information. Database management device, characterized in that.
The method of claim 1, wherein the meta information is
And storage location information of the monitoring information for accessing the monitoring information.
The method of claim 3, wherein the control unit
When receiving a request for the monitoring information from the power system operating system, providing an interface that allows the power system operating system to directly access the monitoring information by returning meta information including storage location information of the monitoring information. Database management device characterized by.
The method of claim 4, wherein the control unit
When the column corresponding to the monitoring data is added or changed, the meta information corresponding to the storage location information is updated.

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