Abstract: A method and apparatus for determining a mapping of a database object to storage layers is provided. According to one aspect, a database server generates views that represent which components of each storage layer store parts of the object. The views are based on information that the database server automatically gathers from one or more vendor libraries. Each library implements a common API. Each storage layer is associated with a library. The database server passes the object's identifier to each library's implementation of a get-mapping routine of the API. A process that is associated with the storage layer that recognizes the object's identifier responds with the identity of one or more components of the storage layer that store one or more parts of the object. The database server recursively uses this information to obtain mappings between storage layer components and underlying storage layer components.

Abstract: A computer system having a kernel for mapping virtual memory address space to physical memory address space. The computer system uses a method for performing an input/output operation. A physical memory buffer is registered with a subsystem, and the physical memory buffer is associated with a first virtual address, a size and a key. The physical memory buffer is dynamically associated with a second virtual address which is different from the first virtual address. As part of an application program an input/output operation is requested regarding the second virtual address. An application table is used to obtain the first virtual address, the key and the size. The first virtual address, the key and the size are supplied to the subsystem. The subsystem uses the first virtual address, the key and the size, to determine the physical memory buffer and performs an input/output operation using the physical memory buffer without intervention of the kernel.

Abstract: A computer system having a kernel for mapping virtual memory address space to physical memory address space. The computer system uses a method for performing an input/output operation. A physical memory buffer is registered with a subsystem, and the physical memory buffer is associated with a first virtual address, a size and a key. The physical memory buffer is dynamically associated with a second virtual address which is different from the first virtual address. As part of an application program an input/output operation is requested regarding the second virtual address. An application table is used to obtain the first virtual address, the key and the size. The first virtual address, the key and the size are supplied to the subsystem. The subsystem uses the first virtual address, the key and the size, to determine the physical memory buffer and performs an input/output operation using the physical memory buffer without intervention of the kernel.

Abstract: A method and apparatus for determining a mapping of a database object to storage layers is provided. According to one aspect, a database server generates views that represent which components of each storage layer store parts of the object. The views are based on information that the database server automatically gathers from one or more vendor libraries. Each library implements a common API. Each storage layer is associated with a library. The database server passes the object's identifier to each library's implementation of a get-mapping routine of the API. A process that is associated with the storage layer that recognizes the object's identifier responds with the identity of one or more components of the storage layer that store one or more parts of the object. The database server recursively uses this information to obtain mappings between storage layer components and underlying storage layer components.