what is the difference between logical data independence and physical data independence?
145800
Logical data independence is the ability to modify the conceptual scheme without making it necessary to rewrite application programs. ... Physical data independence is the ability to modify the physical schema without causing application programs to be rewritten.
16272
Discrete data is information that can only take certain values. ... Continuous data is data that can take any value. Height, weight, temperature and length are all examples of continuous data.
205567
Discrete data have finite values, or buckets. You can count them. Continuous data technically have an infinite number of steps, which form a continuum.
1123573
Logical modeling mainly involves gathering the requirements of the business, with the latter part of logical modeling directed toward the goals and requirements of the database. Physical modeling deals with the conversion of the logical, or business model, into a relational database model.
1354513
The Difference between Logical and Physical Hard Drives As the name suggests, a physical hard drive is the drive itself. ... The logical hard drive refers to the virtual space that is allocated within the drive. Most drives come with a mass of free, unallocated space and contain no partition.
1218337
Logical address is address generated by CPU during execution whereas Physical Address refers to location in memory unit(the one that is loaded into memory). Note that user deals with only logical address(Virtual address). The logical address undergoes translation by the MMU or address translation unit in particular.
1167554
SQL Anywhere uses physical and logical indexes. A physical index is the actual indexing structure as it is stored on disk. A logical index is a reference to a physical index. ... If one does not exist, the database server creates a new physical index and then points the logical index to it.
206042
1 Answer. logical reads - Number of pages read from the data cache. physical reads - Number of pages read from disk.
1081711
Simply put, an ADT (Abstract Data Type) is more of a logical description, while a Data Structure is concrete. Think of an ADT as a picture of the data and the operations to manipulate and change it. A Data Structure is the the real, concrete thing.
418481
The main difference between the two is that in the physical data independence Schema, we have to change the external storage schema, whereas in the logical data independence, we can change the conceptual schema, without having to change the physical schema.
1204867
Logical Memory: Logical memory enables the user to use large amount of memory to store data. ... This enables the Operating System to arrange memory into a logical manner such as assigning a logical address. Virtual Memory: Virtual memory is a part of the secondary memory( say hard disk) which is used as a memory.
869717
A logical topology is how devices appear connected to the user. A physical topology is how they are actually interconnected with wires and cables. ... However, its physical topology is a star, in which every node on the network connects to a central hub.
570745
Logical data model defines the structure of the data elements and set the relationships between them. A Physical Data Model describes the database specific implementation of the data model.
1449326
Discrete data can only take particular values. ... Continuous data are not restricted to defined separate values, but can occupy any value over a continuous range. Between any two continuous data values, there may be an infinite number of others. Continuous data are always essentially numeric.
202873
A logical topology is how devices appear connected to the user. A physical topology is how they are actually interconnected with wires and cables.
367448
What's the difference between a logical DFD and a physical DFD? A logical DFD focuses on the business and business activities, while a physical DFD looks at how a system is implemented. ... The logical DFD describes the business events that take place and the data required for each event.
919539
Each interface has two types of properties assigned to it: physical properties and logical properties. Physical properties are tied to the entire physical port, whereas logical properties affect only that logical portion of the interface represented by unit numbers or channel numbers.