JPH10161917A - Database file update device - Google Patents

Abstract

(57) [Problem] To provide a database file updating device capable of updating data in a remote place almost in real time with a master database configured by a WAN even when a low-speed line is used. It is intended to do so. A means for constantly monitoring a flag indicating the presence or absence of a change in each of a plurality of records in a data file of a master server, and transmitting the record in which the change has occurred to a remote server via a communication network, This is a database file update device provided separately from the master server on the master server side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a remote server having a data file having the same structure as a data file in a database of a master server. The remote server is connected to the master server via a communication network. The present invention relates to a file updating apparatus that can update a remote database and a master database almost simultaneously even if the line is used.

[0002]

2. Description of the Related Art Conventionally, when a database is used from a remote place, a method of connecting a file server with INS64 or the like and constructing a so-called WAN (Wide Area Network) to access the database is adopted. However, with this method, the data transfer speed is slow, so the response is very poor, especially when the data size is large or there are many search items,
Alternatively, when a large number of files are used in a relation, there is a disadvantage that the access speed is reduced so that the file is hardly usable.

In order to solve this drawback, a method of switching to a line with a higher throughput is adopted, or a database having the same structure as that of the master server (parent server) is replaced with a remote server (remote file server). And periodically copy the master server database and send it to a remote server.

[0004]

When the database of the master server is periodically copied as described above, the database of the remote server cannot be copied and sent to the master server. In other words, if copying is performed in both directions, the database of the remote server that does not include the update information is copied as the database of the master server even though the database has been updated on the master server. So
It does not copy in both directions between the master server and the remote server. Therefore, the remote server only refers to the database of the master server.

[0005] When copying from the master server,
Actually, the frequency of the copying cannot be increased. For example, when copying is performed only at night when the database is not used, there is a problem that only data delayed by one day can be referred to.

On the other hand, in the "file control method" described in Japanese Patent Application Laid-Open No. 58-2939, the updating process can be executed without inconsistency between the writing side and the reading side. There is a problem that the reading side and the reading side cannot be updated at the same time.

The "file updating apparatus" described in Japanese Patent Application Laid-Open No. 1-112448 introduces the concept of a virtual file and restores an abnormal file at a high speed. There is a problem that it cannot be updated simultaneously on the local server.

Further, in the “master server file updating device” described in Japanese Patent Application Laid-Open No. 4-71044,
Although the file update can be stored in the temporary file and re-correction of the day can be performed immediately, there is a problem that it cannot be updated at the remote server at the same time.

That is, in the above-mentioned conventional example, although the updating process can be performed without inconsistency between the writing side and the reading side, the updating cannot be performed simultaneously by the master server and the remote server (the file update can be synchronized). There is a problem that the record content of the database file on the master server is different from the record content of the database file on the remote server. Further, in order to repair the difference between the two records, However, there is a problem that requires a high technology.

An object of the present invention is to provide a database file updating apparatus capable of updating data in a remote place almost in real time with respect to a master database constituted by a WAN even when a low-speed line is used. It is intended for.

Further, the present invention provides a database file which can update a master database and data at a remote location almost in real time with respect to a master database constituted by a WAN even when a low-speed line is used. An object is to provide an updating device.

[0012]

According to the present invention, the remote server has a data file having the same structure as the data file in the database of the master server, and the remote server has the data file via the communication network. Connected to the master server,
In a database file update device that updates a data file of a remote server in response to an update of a data file of the master server, a flag indicating whether or not there is a change in each of a plurality of records in the data file of the master server is constantly monitored. A flag monitoring unit, a record capturing unit that captures a record in which the change has occurred when the flag monitoring unit detects that a change has occurred in the record based on the flag, and a record that the record capturing unit captures. Record transmitting means for transmitting to the remote server via a communication network, wherein the flag monitoring means, the record capturing means, and the record transmitting means are provided on the master server side separately from the master server. Is a file updating device for the database.

According to a third aspect of the present invention, a file updating device comprising the flag monitoring means, the record fetching means and the record sending means is provided on the master server side separately from the master server. In addition to the remote server, another file updating device including the flag monitoring unit, the record capturing unit, and the record sending unit is provided. File update device.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic diagram showing a database file updating apparatus FR1 according to one embodiment of the present invention.

[0015] Database file updating device FR1
Is composed of a master server, a remote server, and a communication network.

On the master server side, a master server 10
The remote server is composed of the remote server 20 and the remote server file updating device 2. The communication network is composed of the master server and the remote server. Is to connect.

The master server 10 includes a master database 11, an index file 12, an application 13, and master hardware 14.

The master database 11 has a data file, and this data file has a plurality of records. The index file 12 has an area for storing IDs of a plurality of records in the data file of the database 11 of the master server, and an area for storing flags indicating whether or not the plurality of records have been changed.

The file updating apparatus 1 constantly monitors a flag indicating whether or not there is a change in each of a plurality of records in the data file of the database 11 of the master server, and determines that a change has occurred in the record based on the flag. Upon detection, the record in which the change has occurred is fetched, and the fetched record is sent to the remote server 20 via the communication network.
0 is provided on the master server side.

That is, the file updating device 1 constantly monitors the first flag indicating the presence or absence of a change in each of a plurality of records in the data file of the master server, When the first flag monitoring means detects that the change has occurred, based on the first flag, the first record capturing means captures a record in which the change has occurred, and the first record capturing means Has a first record sending means for sending the fetched record to the remote server via the communication network, wherein the first flag monitoring means, the first record fetching means, and the first The record sending means is an example of a master server-side file updating device provided on the master server side separately from the master server.

The remote server 20 comprises a remote database 21, an index file 22, an application 23, and remote hardware 24.

The remote database 21 has a data file, and this data file has a plurality of records. The index file 22 has an area for storing the IDs of a plurality of records in the data file of the database 21 of the remote server, and an area for storing a flag indicating whether or not the plurality of records have been changed.

The file update device 2 constantly monitors a flag indicating the presence or absence of a change in each of a plurality of records in the data file of the database 21 of the remote server, and determines that a record has been changed based on the flag. When the change is detected, the record in which the change has occurred is fetched, and the fetched record is transmitted to the master server 10 via the communication network.
Aside from 0, it is provided on the remote server side.

That is, the file updating device 2 constantly monitors the second flag indicating whether or not there is a change in each of the plurality of records in the data file of the remote server, When the second flag monitoring unit detects that a change has occurred based on the second flag, a second record capturing unit that captures a record in which the change has occurred, Second record sending means for sending the record taken by the taking means to the master server via the communication network, wherein the second flag monitoring means, the second record taking means, and the second record taking means are provided. Is an example of a remote server-side file update device provided on the remote server side separately from the remote server. .

Next, the operation of the above embodiment will be described.

FIG. 2 shows the operation of the database file updating apparatus FR1 shown in FIG.
10 is a flowchart showing an operation when updating a record of the remote server 20 in response to a change in the record at 0. In FIG. 2, the operations (S1 to S7) described on the left side are operations on the master server side, and the operations (S11 to S13) described on the right side thereof.
Is an operation on the remote server side.

First, all the flags in the index file 12 corresponding to all the records are set to "0". The flag being “0” means that there is no change in the record corresponding to the flag, that is, it is not necessary to update the record corresponding to the flag in the remote server 20. .

FIG. 3 is a diagram showing an example of a record in the data file of the master database 11 and an example of the index file 12 in the above embodiment.

A record in the data file is composed of an ID area for storing an ID of a product name, a product name area for storing a product name, a product type area for storing a product type, and a unit price area for storing a unit price. Have been. The index file includes an ID area for storing an ID of a product name,
It is composed of only a flag area for storing a flag, and is stored in a memory in the file updating device 1.

In FIG. 3, a predetermined product name is shown as an example of the contents of the record in the data file. However, instead of this product, other items such as services, schedules, events, and construction are described. It may be the contents of a record in the data file.

Returning to the flowchart of FIG. 2, when a change occurs among a plurality of records in the data file of the master database 11 (S2), the flag corresponding to the changed record is changed to "1". (S
3). The record may be changed by an operator, and the operator may manually change the flag to “1” with the change of the record. Alternatively, the operator may automatically change the flag with the change of the record. May be changed to "1".

When the file updating apparatus 1 constantly monitors the index file 12 (that is, monitors the flag of “1”) and finds the flag of “1”, the flag of “1” is detected. Is immediately obtained from the index file 12, and the record corresponding to this ID is fetched from the master database 11 (S
4). The file updating device 1 includes a master database 11
Is transmitted to the remote server 20 via the communication network (S5).

The remote server 20 receives the record from the master server 10 (S11), and updates the record in the remote database 21 by copying the received record (S12). When this update operation is completed, the remote server 20 sends an update completion signal to the file update device 1 on the master server side (S1).
3).

The file updating device 1 is provided with a remote server 20
(S6), the flag corresponding to the update completion signal is returned to "0", a record corresponding to the flag is displayed to indicate that no change has occurred, and Display that the record to be updated does not need to be updated on the remote server. When the update completion signal is received from the remote server 20 (S6), only the flag corresponding to the update completion signal is returned to "0", and the record itself in the index file 12 is not deleted.

In the above embodiment, the file updating device 1 constantly monitors the index file 12,
When the flag “1” is found, the remote location database 21 in the remote location server 20 is updated immediately, so that the data at the remote location can be quickly updated even if a low-speed line is used. Here, when the file update device 1 is monitoring the index file 12, the update start timing is delayed by a maximum amount of time for one cycle of the index file 12, but this delay time can be ignored in practice. Remote data can be updated almost in real time.

That is, when the master server 10 is updated,
Since the update time of the remote server 20 is slightly different in time, the inconsistency occurs when the same field is separately updated in both databases 11 and 21 (stored in the same field). Content may differ). In this case, in the above embodiment, the essential solution cannot be made, but in actual business, there are not so many cases where strict synchronization is required, and in most cases it is sufficient to refer to data. . In such a case, if a database having strict synchronization is used, operability is sacrificed unnecessarily.

Further, the index file 12 itself can be used as a journal file (temporary file). That is, when managing an artificial inconsistency between the master server 10 and the remote server 20, The index file 12 can be used.

In the above embodiment, the application software 13 does not directly update the remote database 21 via the communication network, but the application software 13 accesses only the database 11 prepared in the master server 10. Just do it. That is, from the viewpoint of the remote application 23, the database 1
1 is not a real one but a replica.

The contents of the index file 12 include only a flag in addition to the ID.
When a new database is designed, it can be shared with a database file. In this case, the field corresponding to the flag is set to 1 in the field of the database 11.
It is enough to add them.

Since the application software 13 writes the database file in its own server 10, the writing process can be executed in a much shorter time than when updating via a communication network.

FIG. 4 shows the operation of the database file updating apparatus FR1 shown in FIG.
10 is a flowchart showing an operation when updating a record of the master server 10 in response to a change of a record at 0. In FIG. 4, the operations (S21 to S27) described on the left side are operations on the remote server side, and the operations (S31 to S3) described on the right side thereof.
3) is the operation on the master server side.

First, all of the flags in the index file 22 corresponding to all the records on the remote side are set to "0". And
When a change occurs in a plurality of records in the data file in the remote place database 21 (S22),
The flag corresponding to the record in which the change has occurred is changed to "1" (S23).

Then, the file updating apparatus 1 constantly monitors the index file 22 and monitors the flag of "1". When the file updating apparatus 1 finds the flag of "1", it corresponds to the flag of "1". An ID is obtained from the index file 22, and a record corresponding to the ID is taken from the remote database 21 (S24). The file update device 2 sends the record fetched from the remote database 21 to the master server 10 via the communication network (S25).

The master server 10 receives the record from the remote server 20 (S31), and updates the record in the master database 11 by copying the received record (S32). When this update operation is completed, the master server 10 sends an update completion signal to the remote server 20 (S33).

[0045] The file update device 2
(S26), the flag corresponding to this update completion signal is returned to "0", a record corresponding to the flag is displayed to indicate that no change has occurred, and That the record to be updated does not need to be updated on the master server.

In the conventional example in which the database is provided only in the master server, the application software sends the change data generated in the master server to the remote server via the communication network, and the transmitted data sends the changed data to the remote server. , It is impossible to update synchronously between a plurality of databases (data changed in one database of both databases is updated in the other database). On the other hand, in the conventional example in which the databases are separately provided on both the master server and the remote server, it is not necessary to pass the changed data through a communication line, but it is impossible to synchronize and update the plurality of databases. Will be possible.

The above embodiment focuses on the fact that the application software performs not only the original work of data processing and screen display, but also the work of updating using a communication line. Separate the database from the remote server, and separate the "work to update data synchronously" from the above-mentioned original work.
The file updating apparatuses 1 and 2 are provided, and the file updating apparatuses 1 and 2 execute a file updating operation to update the file in real time.
It should be noted that a personal computer may be used as the file updating devices 1 and 2, or a dedicated device may be used.

FIG. 5 is a diagram showing a database file update device FR2 according to another embodiment of the present invention.

Database file updating device FR2
Is to update the remote location database 21 of the remote location server 20 with respect to a record change that has occurred in the master server 10, and does not execute update in the reverse direction. In other words, even if the record is changed in the remote server 20, the master database 11 of the master server 10 is not updated for this change.

The operation of the database file update device FR2 is the same as the operation shown in FIG.

[0051]

According to the first and second aspects of the present invention, a WAN is provided.
In this case, it is possible to update data in a remote place almost in real time even if a low-speed line is used for the master database configured by the above method.

According to the third and fourth aspects of the present invention, the master database and the remote database can be updated almost in real time even if a low-speed line is used for the master database configured by the WAN. It has the effect of being able to.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a database file update device FR1 according to an embodiment of the present invention.

FIG. 2 is a file updating apparatus F for the database shown in FIG.
9 is a flowchart showing an operation of R1, and particularly showing an operation when updating a record of the remote server 20 in response to a change of a record in the master server 10.

FIG. 3 shows a master database 11 in the embodiment.
FIG. 3 is a diagram showing an example of a record in the data file of FIG.

4 is a file updating apparatus F for the database shown in FIG.
9 is a flowchart showing an operation of R1, and particularly showing an operation when updating a record of the master server 10 in response to a change of a record in the remote server 20.

FIG. 5 is a diagram showing a database file update device FR2 according to another embodiment of the present invention.

[Explanation of symbols]

 FR1, FR2: Database file updating device 1, 2, File updating device, 10: Master server, 11: Master database, 12: Index file, 13: Application, 14: Master hardware, 20: Remote server, 21 remote site database 22 index file 23 application 23 remote site hardware

Claims (4)

[Claims] 1. A remote server having a data file having the same structure as a data file in a database of a master server, wherein the remote server is connected to the master server via a communication network. A file updating device for updating a data file of the remote server in response to the update; a flag monitoring means for constantly monitoring a flag indicating whether or not each of a plurality of records in the data file of the master server has changed; When the flag monitoring means detects that a change has occurred in the record based on the flag, a record fetching means for fetching the record in which the change has occurred; Send to the remote server via the communication network And a code sending means; wherein the flag monitoring means, the record fetching means, and the record sending means are provided on the master server side separately from the master server. Update device. 2. The remote server according to claim 1, wherein when the remote server completes updating of the record transmitted to the remote server via the communication network, the remote server sends update completion information to the master server. And transmitting the update completion information from the remote server to the master server, and changing the flag corresponding to the record in which the change has occurred to an update-disabled state. 3. The remote server includes a data file having the same structure as a data file in a database of the master server. The remote server and the master server are connected via a communication network, and the data file of the master server is provided. A file updating device for updating a data file of the remote server and a data file of the remote server, wherein a first flag for constantly monitoring a first flag indicating the presence or absence of a change in each of a plurality of records in the data file of the master server. Monitoring means, and first record capturing means for capturing a record in which the change has occurred when the first flag monitoring means detects that a change has occurred in the record based on the first flag. And the record fetched by the first record fetching means via the communication network. A first record sending unit for sending to the remote server, wherein the first flag monitoring unit, the first record fetching unit, and the first record sending unit are separate from the master server. A master server-side file update device provided on the master server; and a second flag for constantly monitoring a second flag indicating whether or not each of a plurality of records in the data file of the remote server is changed. Monitoring means for notifying that the change has occurred in the record;
When the second flag monitor detects the second record based on the flag of the second record, the second record capturer captures the record in which the change has occurred, and records the record captured by the second record capturer in the communication. Second record sending means for sending to the master server via a network, wherein the second flag monitoring means, the second record fetching means, and the second record sending means are connected to the remote location. A file updating device for a database provided on the remote server side, separately from the server. 4. The remote server according to claim 3, wherein when the remote server completes updating of the record transmitted to the remote server via the communication network, the remote server sends update completion information to the master server. And when the master server receives the update completion information from the remote server, changes the first flag corresponding to the record in which the change has occurred to an update-disabled state. When the master server completes updating of the record transmitted to the master server, the master server sends update completion information to the remote server, and the remote server receives the update completion information from the master server. Then, the second flag corresponding to the record in which the change has occurred is changed to a non-updatable state. File updating device of the database.