File systems and operating systems Most operating systems provide a file system, as a file system is an integral part of any modern operating system. Early microcomputer operating systems' only real task was file management — a fact reflected in their names (see DOS). Some early operating systems had a separate component for handling file systems which was called a disk operating system. On some microcomputers, the disk operating system was loaded separately from the rest of the operating system. On early operating systems, there was usually support for only one, native, unnamed file system; for example, CP/M supports only its own file system, which might be called "CP/M file system" if needed, but which didn't bear any official name at all.
Because of this, there needs to be an interface provided by the operating system software between the user and the file system. This interface can be textual (such as provided by a command line interface, such as the Unix shell, or OpenVMS DCL) or graphical (such as provided by a graphical user interface, such as file browsers). If graphical, the metaphor of the folder, containing documents, other files, and nested folders is often used (see also: directory and folder).
Sharing fileFile sharing is the practice of distributing or providing access to digitally stored information, such as computer programs, multi-media (audio, video), documents, or electronic books. It may be implemented through a variety of ways. Storage, transmission, and distribution models are common methods of file sharing incorporate manual sharing using removable media, centralized computer file server installations on computer networks, World Wide Web-based hyperlinked documents, and the use of distributed peer-to-peer networking (see peer-to-peer file sharing).
peer-to-peer file sharing
Users can use software that connects in to a peer-to-peer network to search for shared files on the computers of other users (i.e. peers) connected to the network. Files of interest can then be downloaded directly from other users on the network. Typically, large files are broken down into smaller chunks, which may be obtained from multiple peers and then reassembled by the downloader. This is done while the peer is simultaneously uploading the chunks it already has to other peers.
File map
MAP files are a type of debugging symbol.
These are typically plain text files that indicate the relative offsets of functions for a given version of a compiled binary.
Image Maps Another Form of the .MAP file is for HTML image maps. An image map is formatted in HTML and creates click-able areas over an provided image.
Block index
Index locking is a technique utilized to maintain index integrity. A portion of an index is locked during a database transaction when this portion is being accesses by the transaction as a result of attempt to access related user data. Also special database system's transactions (not user invoked transactions) may be invoked to maintain and modify an index, as part of a system's self-maintenance activities. When a portion of index is locked by a transaction, other transactions may be blocked from accessing this index portion (blocked from modifying, and even from reading it, depending on lock type and needed operation).
Specialized concurrency control techniques exist for accessing indexes. These techniques depend on the index type, and take advantage of its structure. They are typically much more effective than applying to indexes common concurrency control methods applied to user data. Notable and have been widely researched are specialized techniques for B-trees (B-Tree concurrency control which are regularly utilized as database indexes.
Index locks are used to coordinate threads accessing indexes concurrently, and typically shorter-lived than the common transaction locks on user data. Often they are called in the professional literature latches.
Because of this, there needs to be an interface provided by the operating system software between the user and the file system. This interface can be textual (such as provided by a command line interface, such as the Unix shell, or OpenVMS DCL) or graphical (such as provided by a graphical user interface, such as file browsers). If graphical, the metaphor of the folder, containing documents, other files, and nested folders is often used (see also: directory and folder).
Sharing fileFile sharing is the practice of distributing or providing access to digitally stored information, such as computer programs, multi-media (audio, video), documents, or electronic books. It may be implemented through a variety of ways. Storage, transmission, and distribution models are common methods of file sharing incorporate manual sharing using removable media, centralized computer file server installations on computer networks, World Wide Web-based hyperlinked documents, and the use of distributed peer-to-peer networking (see peer-to-peer file sharing).
peer-to-peer file sharing
Users can use software that connects in to a peer-to-peer network to search for shared files on the computers of other users (i.e. peers) connected to the network. Files of interest can then be downloaded directly from other users on the network. Typically, large files are broken down into smaller chunks, which may be obtained from multiple peers and then reassembled by the downloader. This is done while the peer is simultaneously uploading the chunks it already has to other peers.
File map
MAP files are a type of debugging symbol.
These are typically plain text files that indicate the relative offsets of functions for a given version of a compiled binary.
Image Maps Another Form of the .MAP file is for HTML image maps. An image map is formatted in HTML and creates click-able areas over an provided image.
Block index
Index locking is a technique utilized to maintain index integrity. A portion of an index is locked during a database transaction when this portion is being accesses by the transaction as a result of attempt to access related user data. Also special database system's transactions (not user invoked transactions) may be invoked to maintain and modify an index, as part of a system's self-maintenance activities. When a portion of index is locked by a transaction, other transactions may be blocked from accessing this index portion (blocked from modifying, and even from reading it, depending on lock type and needed operation).
Specialized concurrency control techniques exist for accessing indexes. These techniques depend on the index type, and take advantage of its structure. They are typically much more effective than applying to indexes common concurrency control methods applied to user data. Notable and have been widely researched are specialized techniques for B-trees (B-Tree concurrency control which are regularly utilized as database indexes.
Index locks are used to coordinate threads accessing indexes concurrently, and typically shorter-lived than the common transaction locks on user data. Often they are called in the professional literature latches.
No comments:
Post a Comment