The correct answer: Data independence
Data independence<span> is the type of </span>data<span> transparency that matters for a centralised DBMS. It refers to the immunity of user applications to changes made in the definition and organization of </span>data<span>. Physical </span>data independence<span> deals with hiding the details of the storage structure from user applications.
</span>
The logical<span> structure of the data is known as the 'schema definition'. In general, if a user application operates on a subset of the </span>attributes<span> of a </span>relation<span>, it should not be affected later when new attributes are added to the same relation. Logical data independence indicates that the conceptual schema can be changed without affecting the existing schemas.
</span>
<span>The physical structure of the data is referred to as "physical data description". Physical data independence deals with hiding the details of the storage structure from user applications. The application should not be involved with these issues since, conceptually, there is no difference in the operations carried out against the data.</span>
Using a linear search to find a value that is stored in the last element of an array of 20,000 elements, 20,000 element(s) must be compared.
Answer:
The answer is "2".
Explanation:
In the given question some information is missing, that is "The propagation time for satellite to earth" which is "270 milliseconds" so, the description to this question can be defined as follows:
Given values:
Bandwidth = 64 kbps
Data frames = 512 bytes
Propagation Time (tp ) =270 ms
Change Bandwidth kbps to bps:
1 kb= 1024 bytes
calculated bandwidth= 64 kbps = 64×1024 bps = 65536 bps
1 bytes = 8 bits
512 bytes = 512 × 8 = 4096 bits
Frame length = 4096 bits
Formula
Transmission time (Tt) = Frame length /Bandwidth
Window size = 1+2a
where a = Propagation time/Transmission time
Calculate Transmission time:
Transmission time (Tt) = 4096 / 65536
Transmission time (Tt)= 625 m.sec
Calculate Window size:
Window size = 1+2(270/625)
Window size
= 1+2(0.432)
Window size
= 1+0.864
Window size = 1.864
Window size
= 2
Answer:
technology is a whole means to provide goods needed for the survival and comfort of human life
