Caching of objects in disk-based databases

A method for storing data read from a primary memory device in a secondary memory device for a read/write access by a processing device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects and the data objects being stored at one or more data regions of the secondary memory device, the secondary memory device comprising a plurality of data storage sections each including one or more data regions, the method comprising the steps of:

• determining for each data object an access frequency indicating a number of accesses in a unit time interval;
• and
• storing data objects whose access frequency falls in a predetermined access frequency range in data regions belonging to a same data storage section;
• wherein
• said access frequencies of an access frequency range of an (i+1)-th data storage section are greater than said access frequencies of an i-th data storage section and each access frequency range comprises an upper and a lower access frequency threshold value,
• a data object of said i-th data storage section is moved from the i-th to said (i+1)-th data storage section when said access frequency of said data object is greater than said upper access frequency threshold value and/or a data object of said (i−1)-th data storage section is moved from said (i+1)-th to said i-th data storage section when said access frequency of said data object is smaller than said lower access frequency threshold value.

A method for storing data read from a primary memory device in a secondary memory device for a read/write access by a processing device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects and the data objects being stored at one or more data regions of the secondary memory device, the secondary memory device comprising a plurality of data storage sections each including one or more data regions, the method comprising the steps of:

• determining for each data object an access frequency indicating a number of accesses in a unit time interval;
• and
• storing data objects whose access frequency falls in a predetermined access frequency range in data regions belonging to a same data storage section;
• wherein
• said determined access frequency indicates said number of read accesses, write accesses or read & write accesses to a data object.

A method for storing data read from a primary memory device in a secondary memory device for a read/write access by a processing device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects and the data objects being stored at one or more data regions of the secondary memory device, the secondary memory device comprising a plurality of data storage sections each including one or more data regions, the method comprising the steps of:

• determining for each data object an access frequency indicating a number of accesses in a unit time interval;
• and
• storing data objects whose access frequency falls in a predetermined access frequency range in data regions belonging to a same data storage section;
• wherein
• said access frequencies of an access frequency range of (i+1)-th data storage section are greater than said access frequencies of an i-th data storage section and each access frequency range comprises an upper and a lower access frequency threshold value,
• a data object of said i-th data storage section is moved from the i-th to said (i+1)-th data storage section when said access frequency of said data object is greater than said upper access frequency threshold value and/or a data object of said (i+1)-th data storage section is moved from said (i+1)-th to said i-th data storage section when said access frequency of said data object is smaller than said lower frequency threshold value;
• wherein
• a physical reference is updated when said data object is moved from one data storage section to another data storage section.

A data processing device for processing data stored on a primary memory device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects, comprising:

• a secondary memory device adapted to store the data objects at one or more data regions, said secondary memory device comprising a plurality of data storage sections each including one or more data regions;
• a processing device comprising a read/write device adapted to read and write data objects from and to data regions of said secondary memory device;
• wherein
• said processing device further comprises:
• an access frequency determining device adapted to determine for each data object stored in said data regions of said secondary memory device an access frequency indicating a number of accesses performed by said read/write device in a unit time interval;
• and
• said read/write device is adapted for writing data objects whose determined access frequency falls in a predetermined access frequency range in data regions belonging to said same data storage section.

A data processing device for processing data stored on a primary memory device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects, comprising:

• a secondary memory device adapted to store the data objects at one or more data regions, said secondary memory device comprising a plurality of data storage sections each including one or more data regions;
• a processing device comprising a read/write device adapted to read and write data objects from and to data regions of said secondary memory device;
• wherein
• said processing device further comprises:
• an access frequency determining device adapted to determine for each data object stored in said data regions of said secondary memory device an access frequency indicating a number of accesses performed by said read/write device in a unit time interval;
• and
• said read/write device is adapted for writing data objects whose determined access frequency falls in a predetermined access frequency range in data regions belonging to said same data storage section;
• and wherein
• said access frequencies of an access frequency range of an (i+1)-th data storage section are greater than said access frequencies of an i-th data storage section and each access frequency range comprises an upper and a lower access frequency threshold value,
• said read/write device is adapted to move a data object of said i-th data storage section said i-th to said (i+1)-th data storage section when said access frequency of said data object is greater than said upper access frequency threshold value and/or
• to move a data object of said (i+1)-th data storage section from said (i+1)-th to said i-th data storage section when said access frequency of said data object is smaller than said lower access frequency threshold value.

A data processing device for processing data stored on a primary memory device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects, comprising:

• a secondary memory device adapted to store the data objects at one or more data regions, said secondary memory device comprising a plurality of data storage sections each including one or more data regions;
• a processing device comprising a read/write device adapted to read and write data objects from and to data regions of said secondary memory device;
• wherein
• said processing device further comprises:
• an access frequency determining device adapted to determine for each data object stored in said data regions of said secondary memory device an access frequency indicating a number of accesses performed by said read/write device in a unit time interval;
• and
• said read/write device is adapted for writing data objects whose determined access frequency falls in a predetermined access frequency range in data regions belonging to said same data storage section;
• and wherein
• said determined access frequency indicates said number of read accesses, write accesses or read & write accesses to a data object.

A data base system comprising a primary memory device on which data of the data base system is stored and a data processing device for processing data stored on the primary memory device, the data in the primary memory device being organized as a plurality of data blocks each consisting of one or more data objects, comprising:

• a secondary memory device adapted to store the data objects at one or more data regions, said secondary memory device comprising a plurality of data storage sections each including one or more data regions;
• a processing device comprising a read/write device adapted to read and write data objects from and to data regions of said secondary memory device;
• wherein
• said processing device further comprises:
• an access frequency determining device adapted to determine for each data object stored in said data regions of said secondary memory device an access frequency indicating a number of accesses performed by said read/write device in a unit time interval;
• and
• said read/write device is adapted for writing data objects whose determined access frequency falls in a predetermined access frequency range in data regions belonging to said same data storage section.