JP3840726B2 - Database system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a database system of a computer system that operates online 24 hours a day.
[0002]
[Prior art]
In a computer system such as a monitoring control system that operates online 24 hours a day, equipment information such as equipment to be monitored is managed in a database and is always referred to in operation processing. The facilities will be newly constructed / changed / removed, etc. at the site where they are installed, due to maintenance and changes in the monitoring area. Reflecting this, processing for updating the database, so-called data maintenance is performed.
[0003]
However, if the database is updated during operation, the operation process may be performed with reference to incomplete data that is being updated. To prevent this, two sets of databases with the same structure are prepared. One is used for data reference access in the operation process, the other is used for data maintenance, and all processing is performed after data maintenance. The database for the operational process and the data maintenance is replaced with an unseen timing.
[0004]
This replacement does not physically replace the contents, but simply changes the database that the operation processing and data maintenance process groups should see. As a result, the database can be switched in an instant, and operation is not hindered.
[0005]
Also, when restoring the data maintenance contents without reflecting them in the operation, it is only necessary to restore only the data maintenance database, and the operation processing is not affected.
[0006]
This example is shown in FIG. 7 and will be described in detail. First, as shown to (a) of the figure, the operation process 1 is performing the monitoring control process on-line, referring the equipment data etc. of the database 2A. The data maintenance process 3 copies the contents of the database 2A to the database 2B in advance. This timing may be immediately after the previous maintenance or just before this time.
[0007]
In this state, the process 3 starts data maintenance and updates the contents of the database 2B.
[0008]
Thereafter, the database to be referred to by the operation process 1 and the data maintenance process 3 is changed between the processes of the operation process 1.
[0009]
That is, as shown in FIG. 5B, the operation process 1 refers to the database 2B, and the data maintenance process 3 refers to the database 2A. For example, it may be considered that the database is opened again. After reopening, the structure of both databases is the same, so each process can perform the same processing as before.
[0010]
[Problems to be solved by the invention]
In the conventional system, although the object of data maintenance is usually only a part of the database, the database having the same structure is used as it is for data maintenance, so that the database usage efficiency is lowered.
[0011]
Further, in the supervisory control system, the database is often stored on the memory for improving the performance, and this method is very expensive.
[0012]
An object of the present invention is to provide a database system in which system operation and data maintenance can be performed in parallel using a set of databases.
[0013]
[Means for Solving the Problems]
The present invention does not have double databases, and performs data maintenance using an empty area of one set of databases, and has the following system configuration.
[0014]
In a database system that stores equipment data of a computer system that is operated online, provides the data for system operation, and performs data maintenance in response to the establishment / change / removal of equipment
A table composed of a data record for storing data, a record use flag for managing the use status of the record, a maintenance type for managing the maintenance type, and a change pointer for managing the position of another record for storing the change contents A database serving as a unit element for data storage and a database access routine are provided.
The database access routine includes
At the time of data maintenance for new equipment, the record use flag is searched for an empty record, the record is set to `` use '', the maintenance type is set to `` new '', the new contents are stored in the data record, and the maintenance type is `` removed '' at the time of data maintenance for equipment removal. When the equipment maintenance data maintenance is performed, the record use flag is searched for an empty record, the empty record is set to “use”, the change contents are written in the empty record, the empty record position is written in the change pointer of the original record, and the maintenance type is set. Change it to “Change”
During the data maintenance, the access from the operation process to the data record at the new installation location is denied, and the access from the operation process to the data record at the equipment removal location and the equipment change location is accessed as requested.
[0015]
Further, after the data maintenance, the database access routine accesses the data record from the operation process to the data record at the newly installed facility as requested, and rejects the access from the operation process to the data record at the facility removal site. The access from the operation process to the data record of the equipment change location is characterized in that the data record storing the change content indicated by the change pointer is accessed.
[0016]
In addition, the database access routine, after reflecting the maintenance data to the operation data to the operation process, clears the maintenance type of the data record of the new equipment installation location, the record use flag and the maintenance type of the data record of the equipment removal location Clears, copies the contents of another record that stores the contents of the data change of the equipment change location to the original record, clears the record use flag of the other record, the maintenance type and the change pointer of the original record And a data maintenance main registration means for clearing the record use flag for data maintenance, the maintenance type, and the change pointer.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a database system configuration showing an embodiment of the present invention. The inside of the database 5 is composed of a plurality of tables 5A to 5N.
[0018]
Each of the tables 5A to 5N includes a data record 6 for storing data, a record use flag 7 for managing the use state of each record corresponding to the data record, and whether or not each record has been subjected to data maintenance. Maintenance type 8 to be managed is provided. Further, when the maintenance type is “change”, the change content is stored in an area different from the original content of the record, but a change pointer 9 indicating the record position is provided.
[0019]
The table configured as described above is accessed using the data access routine 10, and the function equivalent to the case where the database referred to by the operation process and the data maintenance process is switched and the database is duplicated is realized.
[0020]
This operation will be described in detail with reference to FIG. First, as shown in FIG. 2 (a), when newly installing equipment or the like in the data maintenance 3, the record use flag 7 is referred to find an empty record, the found record use flag is set to “use”, and the maintenance type 8 is set as “new”, and the new contents are written in the data record 6.
[0021]
Next, when the equipment or the like is removed as shown in FIG. 2B, the maintenance type 8 of the record is “removed”. Further, when the equipment is changed as shown in FIG. 2C, the maintenance type 8 of the record is set to “change”, the record use flag 7 is referred to search for an empty record, and the original “record” is set at the empty record position. At the same time as writing to the “change pointer”, the use flag of the empty record is set to “use” and the change contents are written to the empty record.
[0022]
As described above, the operation process operates as shown in FIG. 3 during the data maintenance. First, as shown in FIG. 3 (a), if there is an access to a new location, the access is denied. Next, when there is an access at the removal location as shown in FIG. 3B or when there is an access at the change location as shown in FIG. 3C, the data record is accessed as requested.
[0023]
By doing so, operation is not affected even during data maintenance.
[0024]
After the data maintenance as described above, the operation when the contents are reflected in the operation is as shown in FIG. It should be noted that even if it is reflected in the operation, no data processing is required at that time, and the database access routine only sees that the record that has undergone maintenance has not been seen. This changes in an instant, and after that, the maintenance contents will be used.
[0025]
Specifically, when a new location is accessed in FIG. 4A, the data record is accessed as requested. When accessing the removal location in FIG. 4B, access is denied. When accessing the changed part in FIG. 4C, the data record indicated by the change pointer is accessed.
[0026]
The above is an access method that instantly reflects the contents of data maintenance in operation. However, the record use flag maintenance type and the contents of the change pointer are in the state immediately after the data maintenance, and they are completely prepared for the next data maintenance. Must be reflected in operational data. This is called regular registration.
[0027]
The operation for this registration is shown in FIG. In FIG. 5A, when performing the main registration of the new location, the maintenance type is cleared. In FIG. 5B, when the removal location is registered as a main item, the record use flag and the maintenance type are cleared. In the case of registering the changed part in FIG. 5C, the change content stored in another record is copied to the original record, and the use flag of the other record, the maintenance type of the original record, and the change pointer are cleared. .
[0028]
As described above, the data maintenance is reflected in the operation data, and the record use flag, the maintenance type, and the change pointer are cleared in preparation for the next data maintenance. This final form is shown in FIG.
[0029]
【The invention's effect】
As described above, according to the present invention, there is provided a database in which a table composed of a record use flag of a data record, a maintenance type, and a change pointer is used as a unit element for data storage. Since the maintenance is performed, the following effects are obtained.
[0030]
(1) Since data maintenance is performed using an empty area in anticipation of future increments, an extra data area for data maintenance is unnecessary, and usage efficiency is improved.
[0031]
(2) The size of the database may be the minimum size required for operation, and the cost can be kept low when the database is mapped to the memory. In addition, even when the memory is limited, it can be mapped to the memory as much as possible, and the performance can be improved.
[0032]
(3) As in the prior art, parallel operations can be performed during data maintenance without affecting operation processing at all.
[0033]
(4) As in the conventional case, after data maintenance, the contents can be instantly reflected in the operation process.
[Brief description of the drawings]
FIG. 1 is a database configuration diagram showing an embodiment of the present invention.
FIG. 2 is a database operation procedure during data maintenance in the embodiment.
FIG. 3 shows a database operation procedure during data maintenance during operation in the embodiment.
FIG. 4 is a database operation procedure after temporary registration of data maintenance during operation in the embodiment.
FIG. 5 is a database operation procedure at the time of data maintenance main registration in the embodiment.
FIG. 6 shows a database state after data maintenance main registration in the embodiment.
FIG. 7 shows a conventional database dual holding method.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Operation process 3 ... Data maintenance process 5 ... Database 5A, 5N ... Table 6 ... Data record 7 ... Record use flag 8 ... Maintenance type 9 ... Change pointer 10 ... Database access routine

Claims (3)

In a database system that stores equipment data of a computer system that operates online, provides the data for system operation, and performs data maintenance in response to the establishment / change / removal of equipment,
A table composed of a data record for storing data, a record use flag for managing the usage status of the record, a maintenance type for managing the maintenance type, and a change pointer for managing the position of another record for storing the change contents A database as a unit element for data storage and a database access routine are provided.
The database access routine includes
At the time of data maintenance for new equipment, the record use flag is searched for an empty record, the record is set to “use”, the maintenance type is set to “new”, and the new contents are stored in the data record. When the equipment maintenance data maintenance is performed, the record use flag is searched for an empty record, the empty record is set to “use”, the change contents are written in the empty record, the empty record position is written in the change pointer of the original record, and the maintenance type is set. Change it to “Change”
During the data maintenance, the access from the operation process to the data record of the new equipment location is denied, and the access from the operation process to the data record of the equipment removal location and the equipment change location is accessed as requested. system. The database access routine, after data maintenance, accesses the data record from the operation process to the data record of the newly installed facility as requested, and denies access from the operation process to the data record of the facility removal location, 2. The database system according to claim 1, wherein a data record storing a change content indicated by the change pointer is accessed for an access from the operation process to the data record at the change location. The database access routine clears the maintenance type of the data record of the newly installed part after the maintenance data is reflected in the operation data to the operation process, and clears the record use flag and the maintenance type of the data record of the equipment removal part. Then, copy the contents of another record storing the change contents of the data record of the equipment change location to the original record, clear the record use flag of the other record, the maintenance type and the change pointer of the original record, 3. The database system according to claim 1, further comprising data maintenance main registration means for clearing the record use flag, maintenance type, and change pointer for data maintenance.

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