Miscellaneous 01

01. ______ is process of extracting previously not known valid and actionable information from large data to make crucial business and strategic decisions.                     [Paper III December 2012]

(A) Data Management

(B) Data base

(C) Data Mining

(D) Meta Data

02. Data Warehouse provides                                             [Paper III June 2012]

(A) Transaction Responsiveness

(B) Storage, Functionality Responsiveness to queries

(C) Demand and Supply Responsiveness

(D) None of the above

03. An example of a dictionary-based coding technique is      [Paper III December 2012]

(A) Run-length coding

(B) Huffman coding

(C) Predictive coding

(D) LZW coding

SOLUTIONS

1. C

2. B

A data warehouse is a database used for reporting and data analysis. It is a central repository of data which is created by integrating data from one or more disparate sources. Data warehouses store current as well as historical data and are used for creating trending reports for senior management reporting such as annual and quarterly comparisons.

The data stored in the warehouse are uploaded from the operational systems (such as marketing, sales etc.,). The data may pass through an operational data store for additional operations before they are used in the DW for reporting.

3. D
Run-length Coding is a very simple form of data compression in which runs of data (that is, sequences in which the same data value occurs in many consecutive data elements) are stored as a single data value and count, rather than as the original run.
Huffman coding is an entropy encoding algorithm used for lossless data compression. The term refers to the use of a variable-length code table for encoding a source symbol.
Predictive coding is a tool used mostly in audio signal processing and speech processing for representing the spectral envelope of a digital signal of speech in compressed form, using the information of a linear predictive model.
Lempel–Ziv–Welch (LZW) is a universal lossless data compression algorithm. A high level view of the encoding algorithm is shown here:

1. Initialize the dictionary to contain all strings of length one.
2. Find the longest string W in the dictionary that matches the current input.
3. Emit the dictionary index for W to output and remove W from the input.
4. Add W followed by the next symbol in the input to the dictionary.
5. Go to Step 2.

A dictionary is initialized to contain the single-character strings corresponding to all the possible input characters (and nothing else except the clear and stop codes if they're being used). The algorithm works by scanning through the input string for successively longer substrings until it finds one that is not in the dictionary