Database managing device

• US 6,549,902 B1
• Filed: 06/09/2000
• Issued: 04/15/2003
• Est. Priority Date: 06/17/1999
• Status: Expired due to Fees

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Iwai, Toshiyuki
• Primary Examiner(s): Metjahic, Safet
• Assistant Examiner(s): NGUYEN, CAM LINH T
• Application Number:
  US09/592,458
• Time in Patent Office: 1,040 Days
• Field of Search: 707/8, 707/500.1, 709/229, 395/425
• US Class Current: 1/1
• CPC Class Codes: G06F 16/2308 Concurrency control transaction processing G06F9/466
• CPC Class Codes: G06F 16/275 Synchronous replication
• CPC Class Codes: Y10S 707/99938 Concurrency, e.g. lock management in shared database

Abstract

An information processing device creates a dirty bit indicative of an update state for each combination of sharing bags between parties. A database processing section updates the dirty bit of a tip by monitoring any modification to the tip during a non-synchronous period. A synchronous process is carried out between two information processing devices, in which whether it is required to transfer the tip and transfer direction are decided after transfer of the dirty bit. Further, the dirty bit which relates to the synchronous process is updated and the update is transferred to the other dirty bit which corresponds to the tip. As a result, it is possible to reduce communication data volume and to find a coincidence in tips between three or more information processing devices, thereby realizing a database managing device which can reduce communication data volume in the synchronous process in a database system in which associating data can be independently updated by a plurality of devices.

Claims

1. A database managing device which includes synchronous process means for finding a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous processes, said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in each of the other database managing devices; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region of one of the other database managing devices,

wherein said database managing device communicates and carries out a synchronous process with the other database managing devices with no central server being provided therebetween, and the synchronous process means carries out the synchronous process between the first sharing region and the second sharing region of one of the other database managing devices one at a time based on the state information associated with the first sharing region and the second sharing region so as to find a coincidence of the two sharing regions, and the synchronous process means updates the state information relating to the second sharing region and transfers the updated state information to state information associated with other second sharing regions.

2. The database managing device as set forth in claim 1, comprising:

data managing number storing means for storing a data managing number which corresponds to each data contained in the first sharing region; and

data managing number setting means for setting the data managing number, said data managing number setting means setting a data managing number for a combination of a database managing number having a value different from that of any of the other database managing devices and a data number having a different value from that of any other data contained at least in the first sharing region with respect to data newly added in the first sharing region by a process other than the synchronous process, and, with respect to data which was added in the synchronous process, said data managing number setting means setting a data managing number which has already been given to the newly added data in the other database managing device,

wherein said synchronous process means specifies the associating data between the databases based on the data managing number.

3. The data managing device as set forth in claim 2, wherein:

said data managing number storing means maintains a data managing number of data even after the data is placed outside of the first sharing region, and

when the data placed outside of the first sharing region is placed inside the first sharing region while its data managing number is being stored in the data managing number storing means, said data managing number setting means sets the data managing number stored in the data managing number storing means for the data.

4. The database managing device as set forth in claim 2, wherein:

said synchronous process means judges whether there is a coincidence in contents of the first data and the second data having the same data managing number, and if coincidence is found, stops transfer of the state information.

5. The database managing device as set forth in claim 2, further comprising:

last update party storing means for storing a last update party of the first data,

wherein said synchronous process means receives a last update party of each data from a sharing party, and when the last update party is said database processing device, stops transfer of the state information of the data.

6. The database managing device as set forth in claim 2, further comprising:

transfer list storing means for storing a transfer list indicative of a last update party and all database managing devices through which information has been transferred since the last update party when transferring the first data while maintaining its contents,

wherein said synchronous process means receives a transfer list of each data from a sharing party, and when said database managing device is included in the transfer list, stops transfer of the state information of the data.

7. The database managing device of claim 1, wherein when carrying out the synchronous process to find a coincidence between the first and second sharing regions, said synchronous process means confirms presence or absence of any update by sending and receiving the state information, and when update is made in a plurality of sharing regions, judges whether the data are the same and decides whether to replace remaining of the associating data with data contents of which party.

8. The database managing device as set forth in claim 7, wherein said synchronous process means judges whether the data are the same based on additional information making up a portion of each data.

9. The database managing device as set forth in claim 8, further comprising:

update party storing means for storing, as the additional information, last update party of the first data,

wherein said synchronous process means judges that the first data and the second data are the same when the last update party of the second data received from a sharing party is said database managing device and when the first data has not been updated.

10. The database managing device as set forth in claim 8, further comprising:

transfer list storing means for storing, as the additional information, a transfer list indicative of a last update party and all database managing devices through which information has been transferred since the last update party when transferring the first data while maintaining its contents,

wherein said synchronous process means judges that the first data and the second data are the same when the transfer list of the second data received from a sharing party includes said database managing device and when the first data has not been updated.

11. The database managing device as set forth in claim 8, further comprising:

updated identification information storing means for storing, as the additional information, updated identification information which is set to have a different value in each update with respect to the first data,

wherein said synchronous process means judges that the first data and the second data are the same when the updated identification information is the same.

12. The database managing device as set forth in claim 8, further comprising:

last updated time storing means for storing, as the additional information, last updated time with respect to the first data,

wherein said synchronous process means judges that the first data and the second data are the same when the last updated time is the same.

13. The device of claim 1, further comprising update means for monitoring operations on the first data so as to update, in the non-synchronous period, the state information of the first data among the state information stored in the state information storing means.

14. A database managing device which includes synchronous process means for finding a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous processes, said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in each of the other database managing devices;

data managing number storing means for storing a data managing number which corresponds to the first data;

data managing number setting means for setting the data managing number, said data managing number setting means setting a data managing number for a combination of a database managing number having a value different from that of any of the other database managing devices and a data number having a different value from that of any other data contained at least in the first sharing region with respect to data newly added in the first sharing region by a process other than the synchronous process, and, with respect to data which was added in the synchronous process, said data managing number setting means setting a data managing number which has already been given to the newly added data in the other database managing device;

state information storing means for storing state information indicative of an update state in a non-synchronous period per each combination of the first sharing region and the second sharing region with respect to the first data contained even once in the first sharing region during the non-synchronous period,

wherein said synchronous process means specifies, based on the data managing number, the first and second data associating with each other so as to find a coincidence in contents of the first and second data referring to the state information,

wherein said data managing number storing means maintains a data managing number of data even after the data is placed outside of the first sharing region, and

when the data placed outside of the first sharing region is placed inside the first sharing region while its data managing number is being stored in the data managing number storing means, said data managing number setting means sets the data managing number stored in the data managing number storing means for the data.

15. The device of claim 14, further comprising update means for monitoring operations on the data whose data managing number is stored in the data managing number storing means so as to update, in the non-synchronous period, state information of the data among the state information stored in the state information storing means.

16. A recording medium recording a database managing program which can update data within its first database in a non-synchronous period between synchronous processes, and which finds a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing program,

said recording medium recording a program for operating a computer, the program being recorded in the form of:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in each of the other database managing devices;

data managing number storing means for storing a data managing number which corresponds to the first data; and

data managing number setting means for setting the data managing number, said data managing number setting means setting a data managing number for a combination of a database managing number having a value different from that of any of the other database managing devices and a data number having a different value from that of any other data contained at least in the first sharing region with respect to data newly added in the first sharing region by a process other than the synchronous process, and, with respect to data which was added in the synchronous process, said data managing number setting means setting a data managing number which has already been given to the newly added data in the other database managing device; and

state information storing means for storing state information indicative of an update state in a non-synchronous period per each combination of the first and second sharing regions with respect to the first data contained even once in the first sharing region during the non-synchronous period,

wherein the program for operating a computer includes a program of synchronous process means which specifies, based on the data managing number, the first and second data associating with each other so as to find a coincidence in contents of the first and second data referring to the state information,

wherein said data managing number storing means maintains a data managing number of data even after the data is placed outside of the first sharing region, and

when the data placed outside of the first sharing region is placed inside the first sharing region while its data managing number is being stored in the data managing number storing means, said data managing number setting means sets the data managing number stored in the data managing number storing means for the data.

17. A recording medium recording a database managing program which can update data within its first database in a non-synchronous period between synchronous processes, and which finds a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing program,

said recording medium recording a program for operating a computer, the program being recorded in the form of:

synchronous process means for finding a coincidence of contents of associating data with the other database managing devices which are to be brought into communications with said database managing program; and

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in each of the other database managing devices,

wherein the program for operating a computer includes a program of synchronous process means which carries out a synchronous process with the second sharing region of one of the other database managing devices at a different time from a synchronous process with another second sharing region when finding a coincidence between the first sharing region and the second sharing region, and carries out the synchronous process with the second sharing region one at a time, so that said program enables a database managing device using the program to communicate and carry out the synchronous process with the other database managing devices with no central server being provided therebetween.

18. A database managing device which includes synchronous process means for finding a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing device, and which includes a database and can update data in the database in a non-synchronous period between synchronous processes, said database managing device comprising:

sub-set setting means for setting, as a portion of the database, a first sub-set which stores data associated with data of the another database managing device;

sub-set associating means for associating the first sub-set with a second sub-set of the another database managing device, which stores data to be associated with the data in the first sub-set;

moved time storing means for storing last moved time with respect to data which was moved in and out of the first sub-set, and

wherein first synchronous process means as the synchronous process means decides whether to place other associating data in their respective sub-sets in accordance with more recent last updated time when finding a coincidence between the first sub-set and the second sub-set.

19. The device of claim 18, further comprising update means for monitoring operations on data whose data managing number is stored in data managing number storing means so as to update, in the non-synchronous period, state information of the data among state information stored in the state information storing means.

20. A recording medium recording a database managing program which can update data within its first database in a non-synchronous period between synchronous processes and which finds a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing program,

said recording medium recording a program for operating a computer, the program being recorded in the form of:

synchronous process means for finding a coincidence of contents of associating data with the another database managing device which is to be brought into communications with said database managing program;

sub-set setting means for setting, as a portion of the first database, a first sub-set which stores data associated with data of the another database managing device;

sub-set associating means for associating the first sub-set with a second sub-set of the another database managing device which stores data to be associated with the data in the first sub-set; and

moved time storing means for storing last moved time with respect to data which was moved in and out of the first sub-set,

wherein the program for operating a computer includes a program of first synchronous process means as the synchronous process means which decides whether to place other associating data in their respective sub-sets in accordance with more recent last updated time when finding a coincidence between the first sub-set and the second sub-set.

21. A database managing device which includes synchronous process means for finding a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing device, and which includes a database and can update data in the database in a non-synchronous period between synchronous processes,

said database managing device comprising:

sub-set setting means for setting, as a portion of the database, a first sub-set which stores data associated with data of the another database managing device; and

sub-set associating means for associating the first sub-set with a second sub-set of the another database managing device, which stores data to be associated with the data in the first sub-set; and

moved number storing means for storing the number of times data was moved in and out of the first sub-set in the non-synchronous period,

wherein second synchronous process means as the synchronous process means decides whether to place other associating data in their respective sub-sets in accordance with data with the greatest moved number when finding a coincidence between the first sub-set and the second sub-set.

22. The device of claim 21, further comprising update means for monitoring operations on data whose data managing number is stored in data managing number storing means so as to update, in the non-synchronous period, state information of the data among state information stored in the state information storing means.

23. A recording medium recording a database managing program which can update data within its first database in a non-synchronous period between synchronous processes, and which finds a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing program,

said recording medium recording a program for operating a computer, the program being recorded in the form of:

synchronous process means for finding a coincidence of contents of associating data with the another database managing device which is to be brought into communications with said database managing program;

sub-set setting means for setting, as a portion of the database, a first sub-set which stores data associated with data of the another database managing device;

sub-set associating means for associating the first sub-set with a second sub-set of the another database managing device, which stores data to be associated with the data in the first sub-set; and

moved number storing means for storing the number of times data was moved in and out of the first sub-set in the non-synchronous period,

wherein the program for operating a computer includes a program of second synchronous process means as the synchronous process means which decides whether to place other associating data in their respective sub-sets in accordance with data with the greatest moved number when finding a coincidence between the first sub-set and the second sub-set.

24. A recording medium recording a database managing program which can update data within its first database in a non-synchronous period between synchronous processes, and which finds a coincidence of contents of associating data with another database managing device to be brought into communications with said database managing program,

said recording medium recording a program for operating a computer, the program being recorded in the form of:

synchronous process means for finding a coincidence of contents of associating data with the another database managing device which is to be brought into communications with said database managing program;

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in the another database managing device; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region,

wherein the program for operating a computer includes a program of the synchronous process means which confirms presence or absence of any update by sending and receiving the state information when carrying out the synchronous process to find a coincidence between the first and second sharing regions, and when update is made in a plurality of sharing regions, judges whether the data are the same and decides whether to replace remaining of the associating data with data contents of which party,

transfer list storing means for storing, as the additional information, a transfer list indicative of a last update party and database managing devices through which information has been transferred since the last update party when transferring the first data while maintaining its contents, and

wherein said synchronous process means judges that the first data and the second data are the same when the transfer list of the second data received from a sharing party includes said database managing device and when the first data has not been updated.

25. A database system comprising a plurality of database managing devices, each of the database managing devices comprising synchronous process means for finding a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous processes, said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in each of the other database managing devices; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region of one of the other database managing devices,

wherein said database managing device communicates and carries out a synchronous process with the other database managing devices with no central server being provided therebetween, and the synchronous process means carries out the synchronous process between the first sharing region and the second sharing region of one of the other database managing devices one at a time based on the state information associated with the first sharing region and the second sharing region so as to find a coincidence of the two sharing regions, and the synchronous process means updates the state information relating to the second sharing region and transfers the updated state information to state information associated with other second sharing regions.

26. A database managing device comprising synchronous process means for finding a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous processes,

said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in the another database managing device; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region of the another database managing device,

wherein when carrying out the synchronous process to find a coincidence between the first and second sharing regions, said synchronous process means confirms presence or absence of any update by sending and receiving the state information, and when update is made in a plurality of sharing regions, judges whether the data are the same and decides whether to replace remaining of the associating data with data contents of which party,

wherein said synchronous process means judges whether the data are the same based on additional information making up a portion of each data,

transfer list storing means for storing, as the additional information, a transfer list indicative of a last update party and all database managing devices through which information has been transferred since the last update party when transferring the first data while maintaining its contents, and

wherein said synchronous process means judges that the first data and the second data are the same when the transfer list of the second data received from a sharing party includes said database managing devices and when the first data has not been updated.

27. A database managing device comprises synchronous process means for finding a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous process,

said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in the another database managing device; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region of the another database managing device,

wherein when carrying out the synchronous process to find a coincidence between the first and second sharing regions, said synchronous process means confirms presence or absence of any update by sending and receiving the state information, and when update is made in a plurality of sharing regions, judges whether the data are the same and decides whether to replace remaining of the associating data with data contents of which party,

wherein said synchronous process means judge whether the data are the same based on additional making up a portion of each data,

updated identification information storing means for storing, as the additional information, updated identification information which is set to have a different value in each update with respect to the first data, and

wherein said synchronous process means judges that the first data and the second data are the same when the updated identification information is the same.

28. A database managing device comprising synchronous process means for finding a coincidence of contents of associating data with another database managing device which is to be brought into communications with said database managing device, and which includes a first database and can update data in the first database in a non-synchronous period between synchronous processes,

said database managing device comprising:

sharing region associating means for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in the another database managing device; and

state information storing means for storing state information indicative of an update state of the first data in the non-synchronous period per each combination of the first sharing region and the second sharing region of the another database managing device,

wherein when carrying out the synchronous process to find a coincidence between the first and second sharing regions, said synchronous process means confirms presence or absence of any update by sending and receiving the state information, and when update is made in a plurality of sharing regions, judges whether the data are the same and decides whether to replace remaining of the associating data with data contents of which party,

wherein said synchronous process means judges whether the data are the same based on additional information making up a portion of each data,

last updated time storing means for storing, as the additional information, last updated time with respect to the first data, and

wherein said synchronous process means judges that the first data and the second data are the same when the last updated time is the same.

29. A method of operating a database managing device comprising:

providing a synchronous process for finding a coincidence of contents of associating data with other database managing devices which are to be brought into communications with said database managing device, and wherein the database managing device includes a first database and can update data in the first database in a non-synchronous period between synchronous processes,

a sharing region associating process for associating a first sharing region making up at least a portion of the first database with a second sharing region for storing second data to be associated with first data in the first sharing region, the second sharing region being at least a portion of a second database which is stored in other database managing devices;

storing state information indicative of an update state of the first data in the non-synchronous period per a combination of the first sharing region and the second sharing region of one of the other database managing devices, wherein said database managing device communicates and carries out a synchronous process with other database managing devices and the synchronous process means carries out the synchronous process between the first sharing region and the second sharing region of one of the other database managing devices one at a time based on the state information associated with the first sharing region and the second sharing region so as to find a coincidence of the two sharing regions, and the synchronous process updates the state information relating to the second sharing region and transfers the updated state information to state information associated with other second sharing regions.