Database management system with rebalance architectures

A database system connected to a plurality of storages for storing a table of data having a plurality of data items, said table data being determined according to a predetermined division rule and stored in the storages, said system comprising:

• rebalance operation means for determining data to be moved from existing storages to an additional storage according to said division rule, copying the determined data from said existing storages to said additional storage, previously adding copy position information in the additional storage to copy source data in the existing storages, and after completing the copy operation of all the data determined to be moved to said additional storage, deleting all the copy source data in said existing storages;
• means for accepting search, update, delete and insert requests for said table data during execution of rebalance operation of said rebalance operation means;
• means, in response to the accepted search request, for performing search operation over data stored in said existing storages;
• means, in response to the accepted update and delete requests, for performing update and delete operations over the data stored in said existing storages, and, when said copy position information is added to data to be updated and deleted, for performing update and delete operations even over data as a copy destination in said additional storage;
• and
• means, in response to the accepted insert request, for storing data to be inserted in one of said existing storages determined according to said division rule before addition thereof in said additional storage, and when said additional storage is a storage destination of said insert object data according to said division rule after addition of said additional storage, for storing said insert object data in said additional storage, and adding storage position information of said insert object data in said additional storage to the insert object data in said existing storages.

A database management method for a database system connected to a plurality of storages for storing a table of data having a plurality of data items, said table data being determined according to a predetermined division rule and stored in the storages, said method comprising the steps of:

• determining data to be moved between the storages according to said division rule due to any one of addition and disconnection of a storage to be connected and moving the determined data for rebalance operation;
• accepting search, update, delete and insert requests to said table data during execution of said rebalance operation in said rebalance operation step;
• in response to the accepted search, update and delete requests, executing search, update and delete operations for said storages;
• and
• in response to the accepted insert request, determining a storage destination of data to be inserted from said storages according to said division rule.

A database management method for a database system connected to a plurality of storages for storing a table of data having a plurality of data items, said table data being determined according to a predetermined division rule and stored in the storages, said method comprising the steps of:

• determining data to be moved from existing storages to an additional storage according to said division rule due to addition of a storage for storing said table data and copying the determined data from said existing storages to said additional storage;
• previously adding copy position information in said additional storage to data as a copy source in said existing storages and, after completing the copy operation of all the data determined to be moved to said additional storage, deleting all the data as the copy source in said existing storages for rebalance operation;
• accepting search, update, delete and insert requests to said table data during execution of said rebalance operation step;
• in response to the accepted search request, performing search operation over the data stored in said existing storages;
• in response to the accepted update and delete requests, performing update and delete operations over the data stored in said existing storages and, when said copy position information is added to data to be updated and deleted, performing update and delete operations even over a copy destination data in said additional storage;
• and
• in response to the accepted insert request, storing the insert object data in one of the existing storages determined according to said division rule before adding said insert object data in said additional storage and, when said additional storage is a storage destination of said insert object data according to said division rule after adding said additional storage, storing said insert object data even in said additional storage and adding storage position information of said insert object data in said additional storage in the insert object data in said existing storages.

A program read into a computer for executing steps for database management, comprising the steps of:

• determining data to be moved between storages according to said division rule due to any one of addition and disconnection of a storage connected and to be connected and moving the determined data for rebalance operation;
• accepting search, update, delete and insert requests over said table data during execution of said rebalance operation of said rebalance operation step;
• in response to the accepted search, update and delete requests, performing search, update and delete operations over said storages;
• and
• in response to the accepted insert request, determining a storage destination of the insert object data from said storages according to said division rule and inserting said insert object data in the determined storage.

A program read into a computer for executing steps for database management, comprising the steps of:

• determining data to be moved from existing storages to an additional storage according to said division rule, copying the determined data from said existing storages to said additional storage, previously adding copy position information in the additional storage to copy source data in the existing storages, and after completing the copy operation of all the data determined to be moved to said additional storage, deleting all the copy source data in said existing storages;
• accepting search, update, delete and insert requests for said table data during execution of rebalance operation of said rebalance operation means;
• in response to the accepted search request, performing search operation over data stored in said existing storages;
• in response to the accepted update and delete requests, performing update and delete operations over the data stored in said existing storages, and, when said copy position information is added to data to be updated and deleted, performing update and delete operations even over data as a copy destination in said additional storage;
• and
• in response to the accepted insert request, storing data to be inserted in one of said existing storages determined according to said division rule before addition thereof in said additional storage, and when said additional storage is a storage destination of said insert object data according to said division rule after addition of said additional storage, for storing said insert object data in said additional storage, and adding storage position information of said insert object data in said additional storage to the insert object data in said existing storages.