JPH0863380A - Database operation method - Google Patents

Abstract

(57) [Summary] [Purpose] To speed up and simplify the above operations for database operation methods in which database migration and storage operations are frequently performed. [Configuration] After online copying an online database constructed by a host computer to a flash memory DB box composed of a plurality of nonvolatile flash memories, this box is connected to another parallel database system. At this time, the data format in each of the flash memories is set to a data format that can be directly accessed by each processing device that constitutes the parallel database. This makes it possible to speed up and simplify the work of backing up the online database and the work of migrating to the parallel database system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a database operating method, and more particularly to a database operating method suitable for frequent database migration and storage operations.

[0002]

2. Description of the Related Art In a conventional database operating method, a magnetic disk device that can be rewritten at high speed and has virtually no limit on the number of times of rewriting is used as a storage medium for retrieving or updating the database and Save (backup) the database in case of occurrence
A magnetic tape, which is a portable medium, is generally used as a storage medium for this purpose (Principle of Database Management, James Martin,
Prentice Hall, 1976, pp. 271-283 / PRINCIPL
ES OF DATA-BASE MANAGEMENT, James Martin, PRENTICE
-HALL, 1976, pp271-pp283). Therefore, when a database created on one database system is used on another database system, the former system backs up the database from the magnetic disk unit to the magnetic tape, and the latter system uses the magnetic disk to copy the magnetic disk. Basically, it was necessary to perform the work of copying the database to the device.

[0003]

Generally, a magnetic tape used for backup is significantly inferior to a magnetic disk device in terms of access speed. When backing up to a tape, there is a problem that the work may take 10 hours or more. In addition, a magnetic tape, which is a portable medium, must be handled by a person without fail when it is mounted on an input / output device, which is a laborious task when the number of windings of the magnetic tape is large. There was a problem that it would become.
Recently, as a countermeasure against this, it has become possible to use a magnetic tape library device having a robot mechanism.
Although this can save manpower, there is a problem that it is expensive and the time required for backup cannot be shortened sufficiently.

[0006] Copying a backed up database for use in another system requires the same time and labor as when backing up. As a countermeasure against this, an operation method in which only the update difference of the database is reflected has been proposed, but this method requires a heavy update work, and thus has a problem that it greatly hinders high-speed search operations. Therefore, as a more drastic solution, an operation method in which both update and search are performed on a parallel database is considered, but this method targets the data that is being updated, so it is possible to perform high-speed operations such as exclusive control. Many problems remain before the realization of execution control, and it has not been put to practical use. In addition, it is not necessary to search across databases that are constantly updated, such as online databases, and it is more realistic to search the database when the update has finished at a certain time. Operation method.

On the other hand, in a database system in which data is frequently updated and the data cannot be lost, it is necessary to always make a backup in case of failure. Also, when a large amount of data that is accumulated and collected in an online database system is used as the search target data in other database systems, database migration work is performed frequently in order to search the freshest data possible. There is a need. Furthermore, it is necessary to simplify the migration work and improve the reliability of the work.

In recent years, a database in a magnetic disk device is searched in parallel by using an SQL reception unit, a dictionary management unit, a database processing unit and the like provided on a parallel computer in which a plurality of processing devices are connected by a high-speed communication path. A parallel database system has been proposed that realizes high-speed search processing by doing so.
4th Annual Conference, "Proposal of DB Relocation Method in Parallel DB Server System", Proc. 4-207,1994 / Proposal of Inquiry Processing Method in Parallel DB Server System, Proc. 4-209,1994). However, a large factor that constitutes the elapsed time when the search process is performed on a large-capacity database is the time taken to read data from the magnetic disk device. Also in the case of a parallel database system, when migrating or backing up the database, transfer the data to a specific processing device to which the magnetic tape device is connected, and then perform the necessary processing such as copying the data in the processing device. Since it is executed, there is a problem that it is not possible to perform processing in parallel more than the number of installed magnetic tape devices.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above problems and provide a database operating method capable of performing database backup and migration operations faster and more easily than ever before.

[0008]

[Means for Solving the Problems]

(1) In order to achieve the above object, the database operating method of the present invention is a database operating method in which the database constructed in the first system is used in the second system, which is required in the first system. During the period of time, a batch copy processing step of collectively copying the contents of the database to a random accessible non-volatile backup medium, and a search targeting the database in the single backup medium in the second system. The search processing step to be performed and the storage processing step of storing the single backup medium that has undergone the search processing step are sequentially executed.

(2) Further, in (1), the single backup medium for a plurality of generations is provided, and the batch copy processing step, the search processing step, and the storage processing step are performed for the single backup medium of each generation. It is cyclically repeated.

(3) Further, in (2), the first system is constituted by an online database system for collecting information in which the database is frequently updated, and the second system only searches the database. Configured by a parallel database system for decision support,
A flash memory D configured by bundling a plurality of nonvolatile flash memory cards as the single backup medium
It is composed of a B box.

[0011]

The operation based on the above configuration will be described.

(1) In the database operating method of the present invention, in the database operating method in which the database constructed in the first system is used in the second system,
A batch copy processing step of batch copying the contents of the database to a random accessible non-volatile backup medium in the first system at a required time; and the second system in the single backup medium. A medium at the time of backup work (collective copy processing step) by sequentially executing a search processing step of performing a search for a database and a storage processing step of storing the single backup medium that has undergone the search processing step. Since there is no need for replacement and the database migration work is only the connection or loading of the single backup medium to the second system, the database backup and migration work can be performed faster and more easily than before. it can.

(2) In (1), the single backup media for a plurality of generations are provided, and the batch copy processing step, the search processing step, and the storage processing step are performed for the single backup media of each generation. By repeating it cyclically, it is possible to perform the backup and migration of the database more easily as a part of a series of operation work without paying special attention to the work of backup and migration of the database.

(3) Further, in (2), the first system is constituted by an online database system for collecting information in which the database is frequently updated, and the second system only searches the database. Configured by a parallel database system for decision support,
A flash memory D configured by bundling a plurality of nonvolatile flash memory cards as the single backup medium
By configuring with the B box, the processing efficiency of the second system is greatly improved by the synergistic effect of the flash memory access speed superior to that of the magnetic disk drive and the search processing performance of the parallel database system, and it is small and lightweight and easy to handle. Since there is no moving part, a highly reliable flash memory DB box can be used to perform the database backup and migration work even faster and more easily.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the database operating method of the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a block diagram showing an example of the configuration of a system for realizing the database operating method of the present invention. In the figure, a flash memory parallel database 1 (corresponding to a "second system" in the claims) is a high-speed communication path 3, which connects a plurality of processing devices 2 and processing devices 2 to each other.
It is composed of a flash memory DB box 4 (corresponding to "single backup medium" in claims) which is a non-volatile storage device storing a database. Each processing device 2 is provided with a DB processing reception unit 7, a DB processing unit 8, and a dictionary control unit 9 which are DB management programs according to the purpose of each processing. In addition, the host computer 5 is a system (corresponding to “first system” in the claims) that collectively copies the search target database in the flash memory parallel database 1 to the flash memory DB box 4. Online database 51 that is frequently updated, and the magnetic disk device 6 that holds the online database 51
have. That is, the flash memory DB box 4 is connected to both the flash memory parallel database 1 and the host computer 5.

FIG. 2 is a diagram showing a detailed configuration of the flash memory DB box in FIG. In the figure, a plurality of flash memory cards 10 are stored in the flash memory DB box 4 so that they can be freely replaced. Each flash memory card 10
According to the storage position in the flash memory DB box 4, when the flash memory DB box 4 is connected to or loaded in the flash memory parallel database 1, the flash memory DB box 4 is connected to different processing devices 2 and accessed in parallel. . Note that the flash memory DB box 4 can be easily realized by simply bundling a plurality of flash memory cards 10 together with appropriate spacers.

As a characteristic point of the flash memory card 10, the number of times of rewriting is limited (about 10,000 times),
The access speed is lower than that of the main storage device and higher than that of the magnetic disk device, and even if the storage capacity of a single unit is small, a large capacity comparable to the magnetic disk device can be obtained by combining several disks. Similarly, it is non-volatile (memory can be retained even when power is not supplied),
It is small and lightweight and can be easily attached to and detached from the system. Therefore, the flash memory DB box 4 having the above-described configuration can be accessed at a higher speed than a magnetic disk device used in a normal database, and a storage capacity equivalent to that of the magnetic disk device is secured by combining a plurality of sheets. Various advantages that the database can be divided and held in multiple flash memories are suitable for parallel search processing, and because it is non-volatile, small and lightweight, and easy to attach and detach, it is also suitable for data backup storage. have.

FIG. 3 is a block diagram for explaining the details of the flash memory parallel database in FIG.
In the figure, the DB management program in each processing device 2 includes a DB processing acceptance unit 7, a DB processing unit 8, and a dictionary control unit 9. When the DB processing reception unit 7 receives the search request, the division information 901 stored in the dictionary managed by the dictionary control unit 9 is received.
Are requested and referred to through the high-speed communication path 3. Since the division information 901 defines the division position of the database portion which is divided and stored in each flash memory card 10 which constitutes the flash memory DB box 4, by referring to the division information 901, The processing device 2 connected to the flash memory card 10 can be known. The DB processing reception unit 7 displays the division information 901.
The flash memory card 1 in which the data to be searched in response to the search request is stored by referring to
A processing device 2 having a DB processing unit 8 connected to 0
Then, the search request is distributed to the processing device 2 through the high-speed communication path 3. Upon receipt of this, the DB processing unit 8
According to the distributed request, the database portion 802 divided and stored in the connected flash memory card 10
Is moved to the DB buffer 801 existing on the main storage device in the processing device 2 and a necessary search process is performed. In this way, the results retrieved by the respective DB processing units 8 are aggregated by the DB processing acceptance unit 7 and returned to the retrieval request source as the final retrieval result.

FIG. 4 is a flow chart showing the flow of operation processing in the database operation method of the present invention.
Here, the database (DB) 6 managed by the online database 51 in the host computer 5 is
A case where the flash memory parallel database 1 is introduced for the purpose of performing an atypical and high-speed search will be described. In the following description, it is assumed that at least two flash memory DB boxes 4 having the same configuration are provided.

First, the DB 6 managed by the online database 51 of the host computer 5 is put in a write-protected state (step 401). And step 402
In the flash memory DB box 4, which is the oldest backup of the online database 51 of the host computer 5 among the plurality of flash memory DB boxes 4, the online database 51 of the host computer 5 is stored in parallel database format in advance. Also, the database is backed up (overwritten) so that it is divided on the basis of the division information 901 defined as above and each database portion is stored in each flash memory card 10. Here, even if the partition information 901 is not defined in the host computer 5 in advance,
It is also conceivable that the flash memory parallel database 1 may be searched and obtained via a network when needed. At the time of the above backup, the online database 6 is not written and is in a static state, so the backup as a complete database is completed.

Next, the backed up flash memory DB box 4 is stored in the flash memory parallel database 1
(Step 403). At this time, it is assumed that the data divided according to the division information 901 defined in the dictionary in the flash memory parallel database 1 in advance is stored in each flash memory card 10. In the flash memory parallel database 1, the database in the old flash memory DB box 4 and the database in the new flash memory DB box 4 are switched (step 40).
4). And the previous flash memory DB box 4
When there is no reference to the internal database, the flash memory DB box 4 is removed and saved as a backup (step 405).

By repeating the above-mentioned operation cycle, the online database 51 of the host computer 5 is released from the heavy search, while the flash memory parallel database 1 uses the database only for the search for the flash memory DB box 4. Since it is not necessary to be aware of updating the data, the exclusion process can be greatly simplified. Further, by saving the flash memory DB box 4 in which the database is backed up for several generations, it is possible to minimize the damage when a failure occurs. Nevertheless, the above operation cycle does not require more complicated work than the normal backup operation, and the access speed of the flash memory card 10 as the backup medium is superior to that of the conventional magnetic disk device or magnetic tape device. The backup operation itself can be performed in a shorter time than before.

FIG. 5 is a block diagram showing another example of the configuration of a system that realizes the database operating method of the present invention, in which a part of the processing devices 2 in the parallel computer is hosted by the host.
It is used as the computer 5 inside and the parallel database is arranged in the remaining part, and the flash memory card 10
With regard to the above, by changing the processing device 2 to be connected by hardware switching, the above operation cycle is fully automatically operated. That is, in FIG.
A parallel computer to which a plurality of flash memory DB boxes 4 can be connected is programmed in advance so that the above operation cycle is executed at regular time intervals, and the (new) flash memory DB box 4 on the database side in charge of online processing is programmed. Simultaneously with the end of backup work, the (new) flash memory DB box 4 is switched to the parallel database side in charge of the atypical search processing, and the parallel database side ends the reference to the (reference) flash memory DB box 4 that was the search target. As soon as the flash memory DB box 4 is referenced, the flash memory DB box 4 is disconnected. The (reference) flash memory DB box 4 thus separated automatically serves as a backup for storage. On the side of the database that is in charge of online processing, switching is performed so that the oldest flash memory DB box 4 (where the database was backed up most recently) becomes the backup target at the time of the next backup. If backup to another medium is required, the flash memory D must be offline.
It is also possible to make a copy from the B box 4.

[0025]

【The invention's effect】

(1) As described in detail above, according to the database operation method of the present invention, in the database operation method in which the database constructed in the first system is used in the second system, Batch copy processing step of batch-copying the contents of the database to a single non-volatile backup medium that can be randomly accessed at a required time, and searching for the database in the single backup medium in the second system By sequentially performing the search processing step of performing the search processing and the storage processing step of storing the single backup medium that has undergone the search processing step, it becomes unnecessary to replace the medium during the backup operation (collective copy processing step). , The database migration work is the second system of the above single backup medium. Since it is only connected to or loaded into the system, there is an effect that the backup and migration of the database can be performed faster and more easily than before.

(2) Further, in (1), the single backup media for a plurality of generations are provided, and the batch copy processing step, the search processing step, and the storage processing step are performed for the single backup media of each generation. By repeating it cyclically, there is an effect that it is possible to more easily carry out the backup and migration work of the database as a part of a series of operation work without paying special attention to the work.

(3) Further, in (2), the first system is constituted by an online database system for information collection in which the database is frequently updated, and the second system only searches the database. Configured by a parallel database system for decision support,
A flash memory D configured by bundling a plurality of nonvolatile flash memory cards as the single backup medium
By configuring with the B box, the processing efficiency of the second system is greatly improved by the synergistic effect of the flash memory access speed superior to that of the magnetic disk drive and the search processing performance of the parallel database system, and it is small and lightweight and easy to handle. Since there is no moving part, the use of a highly reliable flash memory DB box has the effect that the backup and migration of the database can be carried out even faster and more easily.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of a system that realizes a database operating method of the present invention.

FIG. 2 is a diagram showing a detailed configuration of a flash memory DB box in FIG.

FIG. 3 is a block diagram for explaining details of a flash memory parallel database in FIG.

FIG. 4 is a flowchart showing the flow of operation processing in the database operation method of the present invention.

FIG. 5 is a block diagram showing another configuration example of a system that realizes the database operating method of the present invention.

[Explanation of Codes] 1 Flash memory parallel database 2 Processing device 3 High-speed communication path 4 Flash memory DB box 5 Host computer 6 Magnetic disk device as database 7 DB processing acceptance part of DB management program 8 DB processing part of DB management program 9 Dictionary control unit of DB management program 10 Flash memory card 51 Online database 801 DB buffer 802 Database part stored in split 901 Partition information

Claims (3)

[Claims] 1. A method of operating a database, wherein a database constructed in a first system is used in a second system, comprising: a nonvolatile nonvolatile memory capable of randomly accessing the contents of the database at a required time in the first system. A batch copy processing step of batch copying to a single backup medium; a search processing step of performing a search for the database in the single backup medium in the second system; and the single processing after the search processing step. A method of operating a database, which comprises sequentially performing a storage processing step of storing a backup medium. 2. The single backup medium for a plurality of generations is provided, and the batch copy processing step, the search processing step, and the storage processing step are cyclically repeated for the single backup medium of each generation. The method of operating a database according to claim 1. 3. The parallel database system for decision support, wherein the first system is constituted by an online database system for collecting information in which the database is frequently updated, and the second system is only for searching the database. And a flash memory D configured by bundling a plurality of nonvolatile flash memory cards as the single backup medium.
A B box is used for the construction.
Or the operation method of the database described in 2.