logical physical ---------- -----------
1.it is an abstract 1.it is in detail.
2.it include the process chat. 2.it includes the organisationl chat.
3.it involves soft copy. 3.it involves the hard copy.
4.it represents the module. 4.it represents the electronics system.
While physical tags are also referred to as presentational mark-up, logical tags are useless for appearances. Physical tags are newer versions while logical tags are old and concentrate on content.
For a physical Data Flow Diagram you explore into the logical DFD. for example, if you have a data flow arrow declared as "customer information" now the physical DFD would include in that data flow arrow "customer information = customer_name + customer_address". something along these lines Physical DFD shows how various functions are performed and who does them but Logical DFD strips away all physical constraints but does not restrict physical happenings from taking place.
Conceptual designs attempts to identify the highest level of relationships between entities. Conceptual designs include only important entities. Physical design helps in converting the logical design into the physical form.
In the 8086/8088 the physical address and logical address have the same importance, because they both relate to the address of the operand. It is true that the offset (logical) address is added to the segment address to determine the physical address, but the limitations of the architecture of the processor forces programmers to consider both.If you are talking about a virtual environment, however, such as in the 80286 or higher, then the logical address is more important than the physical address, because the logical address is the address of the operand, while the physical address is (somewhat) arbitrarily assigned by the operating system.
logical data : refer to the immunity of the external scheme towards changes in the conceptual scheme.physical data: refer to the immunity of the conceptual scheme towards changes in the internal scheme.
difference between physical and logical data flow diagrams.
Network architecture refers to the design and structure of a network, including components, protocols, and technologies used for communication. Network topology, on the other hand, refers to the physical or logical layout of devices and how they are connected in a network, such as bus, star, ring, or mesh. In essence, network architecture defines how components work together, while network topology defines how components are arranged.
Logical topologies consist of virtual connections between nodes.
In computer architectures, a logical address is the address at which a memory location appears to reside from the perspective of an executing application program. This may be different from the physical address due to the operation of a memory management unit (MMU) between the CPU and the memory bus. Physical memory may be mapped to different logical addresses for various purposes. For example, the same physical memory may appear at two logical addresses and if accessed by the program at one address, data will pass through the processor cache whereas if it is accessed at the other address, it will bypass the cache.
While physical tags are also referred to as presentational mark-up, logical tags are useless for appearances. Physical tags are newer versions while logical tags are old and concentrate on content.
the logical data independence is hard to achieve because all the manipulation is belonging in logical data independence but in physical data independence only show the physical view .
The concept of a logical address space is simply involved the process of mapping the Logical addresses to their Physical Addresses . Logical addresses are generated by the CPU; also referred to as virtual addresses.while Physical Address is the actual address of the data stored on the physical device and mapped by MMU.
three similarities is that physical file deals with does file that a
* Physical file (PF) contains the data and have only one record format. Logical file (LF) is a view of the physical file which does not contain any data may be based on one physical file or more then one physical file. Logical file can have more then one record format. Logical can be non join or join logical file. Performance becomes better if you use the logical file in the program.
A physical network is different from a logical network. Logical networks are defined at the Network layer by the arrangement of the hierarchical addressing scheme. Physical networks represent the interconnection of devices on a common media. Sometimes, a physical network is also referred to as a network segment
Physical topology are says how the wire are interconnected, while Logical topology is how the network behaves and interoperates.Sk wasim ul HaqueKharagpur, Madpur
The logical database is how the data is percieved in the tables, the way the data is actually stored on the storage medium is the physical view of the database.