Management system and management method for managing data units constituting schemas of a database

A non-transitory computer readable storage medium storing a computer program that causes a computer to manage a plurality of data units constituting one or more schemas of a database in a storage apparatus,

• wherein the storage apparatus includes a plurality of first storage device sets having a plurality of storage areas, and
• wherein an ordered schema constituted of the plurality of data units having order properties defining respective orders is included in the one or more schemas,
• the computer program causing the computer to:
• determine whether a second storage device set, which is a set of one or more second storage devices and in which each of the storage areas is a free storage area, is added to the first storage device set;
• and
• when a result of a determination is affirmative, migrate two or more data units not consecutive in the order among the plurality of data units stored in the plurality of storage areas in the first storage device set respectively from at least the one first storage device set to the free storage areas of the second storage device set based on based on management information including mapping information as information indicating which data unit constituting the ordered schema is stored in which storage area and order information indicating the order of the data units, such that a plurality of the free storage areas is distributed over the first storage device sets and the second storage device set;
• wherein the number of the first storage device sets is P (P is an integer equal to or larger than 2), each of the first storage devices includes Q storage areas (Q is an integer equal to or larger than 1), and therefore, the P first storage device sets include the (P×Q) storage areas,
• wherein the P data units consecutive in the order are stored in the P storage areas of the same row in the different first storage device sets in units of the P data units consecutive in the order, and
• wherein the computer program causes the computer to migrate the X-th oldest data unit (X is an integer and X=0, 1, . . . , (Q−1)) of the X-th first storage device set from the storage area of the X-th first storage device set to the free storage area of the second storage device set in (A).

A method of managing a plurality of data units constituting one or more schemas of a database in a storage apparatus,

• wherein the storage apparatus includes a plurality of first storage device sets having a plurality of storage areas, and
• wherein an ordered schema constituted of the plurality of data units having order properties defining respective orders is included in the one or more schemas,
• the method comprising:
• determining whether a second storage device set, which is a set of one or more second storage devices and in which each of the storage areas is a free storage area, is added to the first storage device set;
• when a result of a determination is affirmative, migrating two or more data units not consecutive in the order among the plurality of data units stored in the plurality of storage areas in the first storage device set respectively from at least the one first storage device set to the free storage areas of the second storage device set based on based on management information including mapping information as information indicating which data unit constituting the ordered schema is stored in which storage area and order information indicating the order of the data units, such that a plurality of the free storage areas is distributed over the first storage device sets and the second storage device set;
• and
• migrating, when there are the plurality of first storage device sets, the same number of the data units from the respective first storage device sets to the second storage device set by sequentially switching the first storage device set from which to select the data unit to be migrated to the second storage device set.