Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: Method and means are provided for simulating a contiguous data space within a computer memory, and for placing and accessing data objects of various sizes within the simulated contiguous data space. Multiple, sub-data spaces are concatenated in such a way that each page and each sub-data space in the contiguous data space are uniquely identified. Data objects are placed in the contiguous data space and at the first reference to a page of the data object, only the segment containing the referenced page in the contiguous data space is mapped to the database storage disk. Once a data space page is mapped, the operating system can read the page into memory without requesting a disk operation from the database manager. On modifying a page, if the database disk page location is changed, the contiguous data space page is remapped without changing the page address in the data space.

Abstract: A computer system for processing and committing data comprises a processor, an external storage device such as DASD or tape coupled to the processor, and a working memory such as RAM. An application program updates data in the working memory and then requests that the data be committed, i.e. written to the external storage device. In response, an operating system function determines which data or blocks have been changed and supplies to an I/O service an identification of the changed data or blocks to cause the I/O service to write the changed data or blocks to the external storage device. Thus, the application program is not burdened with the management of the I/O. The operating system permits the program to continue with other processing while the data is being written from the working memory to the external storage device. As a result, the program need not wait while the data is written to the external storage.