DIFFERENCE BETWEEN PDF & DOC

PDF vs DOC

PDF and Doc are the two most common and user friendly documentation formats till date. These two types have their own individual standard where they stand out. PDF is an abbreviation of Portable Document Format which is an open format for document exchange. It is utilized for signifying 2D documents in a way free of the application software or operating system. It is an advanced format which enables 2D vector graphics along with 3D drawings and a variety of other data formats. On the other hand, Doc is the abbreviation for document which is the file extension used for a document produced with Microsoft Word, the undeniably accepted word processing program. Doc format is generally employed in MS Word’s versions of 97 and 2003. The later updated version of 2007 employs a different format.

PDF format

The first version of PDF was formally launched in 1991. Its adoption in the beginning days was sluggish. Adobe Acrobat was not generously available. The earlier versions of PDF didn’t have any external hyperlinks support, dropping its utility on the Internet. But gradually Adobe has improved this format to an untouchable quality so that now it is most admirable in its field.

PDF is compatible with Windows, Linux, Mac, to even recent mobile phones. It is compact & small. When a document is converted into PDF, it is automatically optimized in a smaller size without losing the quality. It restricts people from altering your work. The encrypted protection facilitates to share your work, without worrying about diverse doom scenarios. PDF files are viewable in any web-browser without any hazard. PDF is easy to deal with as Acrobat Reader software to open PDF files is free to download.

Doc format

MS-Word was made in 1983 first for Xenix systems with the name of Multi-Tool Word. Afterward newer versions were created for several new platforms like DOS in 1983, Macintosh of Apple in 1984, and Windows in 1989. The Microsoft Word software has the ability to produce and distribute documents utilizing a writing tool set. It is possible to include formatted text, tables, graphs, charts, images, print settings and page formatting in these documents.

A doc file employs a binary file format for gathering the documents on a store media for using by computers. The doc format was developed over a phase of time and now it can be generated and read by software applications such as KWord, OpenOffice, or AbiWord.

	PDF	DOC
File extension	.pdf	.doc
Developer	Adobe Systems	Microsoft
Initial release	1993	1983
Open standard	Yes	No
Definition	PDF, an abbreviation of Portable Document Format, is an open format for document exchange.	DOC/doc, an abbreviation of document, is a filename extension for word processing documents.
Reading software	Adobe Acrobat Reader	MSWord, KWord, OpenOffice, or AbiWord
Compatibility	Windows, Linux, Mac and smart phones	Systems that have accessibility to word reading software
Protection	Can be password protected; does not allow editing; retains exact appearance	Difficult to password protect; can be edited by anyone with Word; can change format if not available
Uses	Legal documents, online transfer, business documents, e-books, etc	Writing and editing documents, memos, letters, projects, etc
Benefits	High quality printing, online availability, archiving, protection, combines multiple formats, free viewing software, smaller file size	Reusing images and text, word processing, editing

MCQ ON “Relational Database and Database Schema”

Database Questions & Answers on “Relational Database and Database Schema”

1. A relational database consists of a collection of
a) Tables
b) Fields
c) Records
d) Keys

Answer:a
Explanation:Fields are the column of the relation or tables.Records are each row in relation.Keys are the constraints in a relation .

2. A ________ in a table represents a relationship among a set of values.
a) Column
b) Key
c) Row
d) Entry

Answer:c
Explanation:Column has only one set of values.Keys are constraints and row is one whole set of attributes.Entry is just a piece of data.

3. The term _______ is used to refer to a row.
a) Attribute
b) Tuple
c) Field
d) Instance

Answer:b
Explanation:Tuple is one entry of the relation with several attributes which are fields.

4. The term attribute refers to a ___________ of a table.
a) Record
b) Column
c) Tuple
d) Key

Answer:b
Explanation:Attribute is a specific domain in the relation which has entries of all tuples.

5. For each attribute of a relation, there is a set of permitted values, called the ________ of that attribute.
a) Domain
b) Relation
c) Set
d) Schema

Answer:a
Explanation:The values of the attribute should be present in the domain.Domain is a set of values permitted .

6. Database __________ , which is the logical design of the database, and the database _______,which is a snapshot of the data in the database at a given instant in time.
a) Instance, Schema
b) Relation, Schema
c) Relation, Domain
d) Schema, Instance

Answer:d
Explanation:Instance is a instance of time and schema is a representation.

7.Course(course_id,sec_id,semester)
Here the course_id,sec_id and semester are __________ and course is a _________ .
a) Relations, Attribute
b) Attributes, Relation
c) Tuple, Relation
d) Tuple, Attributes

Answer:b
Explanation:The relation course has a set of attributes course_id,sec_id,semester .

8. Department (dept name, building, budget) and Employee (employee_id , name, dept name,salary)
Here the dept_name attribute appears in both the relations .Here using common attributes in relation schema is one way of relating ___________ relations.
a) Attributes of common
b) Tuple of common
c) Tuple of distinct
d) Attributes of distinct

Answer:c
Explanation:Here the relations are connected by the common attributes.

9. A domain is atomic if elements of the domain are considered to be ____________ units.
a) Different
b) Indivisbile
c) Constant
d) Divisible

Answer:b
Explanation:None.

10. The tuples of the relations can be of ________ order.
a) Any
b) Same
c) Sorted
d) Constant

Answer:a
Explanation:The values only count .The order of the tuples does not matter.

MCQ ON " KEYS "

Database Questions & Answers on “Keys”

1. Which one of the following is a set of one or more attributes taken collectively to uniquely identify a record?
a) Candidate key
b) Sub key
c) Super key
d) Foreign key

Answer:c
Explanation:Super key is the superset of all the keys in a relation.

2. Consider attributes ID , CITY and NAME . Which one of this can be considered as a super key ?
a) NAME
b) ID
c) CITY
d) CITY , ID

Answer:b
Explanation:Here the id is the only attribute which can be taken as a key. Other attributes are not uniquely identified .

3. The subset of super key is a candidate key under what condition ?
a) No proper subset is a super key
b) All subsets are super keys
c) Subset is a super key
d) Each subset is a super key

Answer:a
Explanation:The subset of a set cannot be the same set.Candidate key is a set from a super key which cannot be the whole of the super set.

4. A _____ is a property of the entire relation, rather than of the individual tuples in which each tuple is unique.
a) Rows
b) Key
c) Attribute
d) Fields

Answer:b
Explanation:Key is the constraint which specifies uniqueness.

5. Which one of the following attribute can be taken as a primary key ?
a) Name
b) Street
c) Id
d) Department

Answer:c
Explanation:The attributes name , street and department can repeat for some tuples.But the id attribute has to be unique .So it forms a primary key.

6. Which one of the following cannot be taken as a primary key ?
a) Id
b) Register number
c) Dept_id
d) Street

Answer:d
Explanation:Street is the only attribute which can occur more than once.

7. A attribute in a relation is a foreign key if the _______ key from one relation is used as an attribute in that relation .
a) Candidate
b) Primary
c) Super
d) Sub

Answer:b
Explanation:The primary key has to be referred in the other relation to form a foreign key in that relation .

8. The relation with the attribute which is the primary key is referenced in another relation. The relation which has the attribute as primary key is called
a) Referential relation
b) Referencing relation
c) Referenced relation
d) Referred relation

Answer:b
Explanation:None.

9. The ______ is the one in which the primary key of one relation is used as a normal attribute in another relation .
a) Referential relation
b) Referencing relation
c) Referenced relation
d) Referred relation

Answer:c
Explanation:None.

10. A _________ integrity constraint requires that the values appearing in specified attributes of any tuple in the referencing relation also appear in specified attributes of at least one tuple in the referenced relation.
a) Referential
b) Referencing
c) Specific
d) Primary

Answer:a
Explanation:A relation, say r1, may include among its attributes the primary key of another relation, say r2. This attribute is called a foreign key from r1, referencing r2. The relation r1 is also called the referencing relation of the foreign key dependency, and r2 is called the referenced relation of the foreign key.

8 Bit and 16 Bit Color

Difference between 8 Bit and 16 Bit Color

Key Difference: 8 bit and 16 bit color describe two different types of graphics mode in which the image formation is stored in a computer’s memory or an image file. In an 8 bit mode, each pixel is denoted by one 8 bit byte. On the other hand, in a 16 bit color mode, each pixel is denoted by two bytes.

Digital images are colored by the combination of three primary colors of light. These colors are red, green and blue. The combination of these three colors generates billions of colors. In eight bit color graphics each pixel is represented or depicted by using an 8 bit byte. It can be expressed as  "2 to the exponent 8", or "2 x 2 x 2 x 2 x 2 x 2 x 2 x 2", which gives the number 256.

Thus, it contains 256 tonal values. It means that 256 shades of red, 256 shades of green and 256 shades of blue are available in 8 bit color mode. The combination of all these shades means 16.8 million possible colors. In eight bit color, 3 bits for red and 3 bits for green are assigned. Rest of the bits (2 bits) are used for the blue component.

On the other hand, in sixteen bit color graphics each pixel is represented or depicted by using a sixteen bit byte. It can be expressed by the expression “2 to the exponent 16”. This is equivalent to 65,536. It would also refer to 65536 shades of green, 65536 shades of red and similarly 65536 shades of blue. This has the possibility of generating 281 trillion colors.

In sixteen bit color, 5 bits are used for red, 6 bits for green, and 5 bits for blue component. This color mode gives many advantages over the 8 bit color mode. For example - it ensures smooth gradation of tone and color. It retains this feature even on making adjustments like contrast, etc. On the other hand, the file of the size becomes greater by using a 16 bit color mode.

Comparison between 8 bit and 16 bit color:

	8 Bit Color	16 Bit Color
Definition	Each pixel in the image is represented by a single byte	Each pixel in the image is represented by two bytes
Possible tonal values per channel	256	65536
File size	Comparatively Less	Almost Double
File Types	JPEG	TIFF
Use	Painters generally use 8 bit color allowing for efficient memory and resource usage.	Photographers normally use 16 bit color since they are more likely to be working with RAW images.
Color Gradation	Less smoother	More smoother

Data Warehouse and Data Mart

Difference between Data Warehouse and Data Mart

Key Difference: Data Warehouse is a big central repository of historical data. This data is assembled from different departments and units of the company. Data Mart can be considered as a subset of data warehouse or simply a data repository which is generally focused on a single functional area. They both primarily vary in their scope and usage area.

Basically, a data warehouse is a collection of data which is isolated from the operational systems. It assists in the decision making of the company. The data is assembled from multiple sources in order to provide accurate and timely information. The data is stored from a historic perspective.

The data in the warehouse is information which has been extracted efficiently from multiple functional units. It is checked, cleaned and finally integrated to be a part of the warehouse. Data warehouses are controlled and implemented by a central organizational unit.

A data mart is an important subset of a data warehouse. It is specifically subject oriented, and it is designed to meet the needs of a specific group of users. Data marts can be individually designed for departments like Sales, Finance, etc.

Data marts are generally controlled by a single department of an organization. The data for these data marts is assembled only from a few sources. Thus, data mart and data warehouse mainly differ in their scope and data sources. Data marts are generally less than 100 GB in size, whereas the size of a data warehouse is typically larger than 100 GB. Due to the difference in scope, it is comparatively easy to design and use data marts. However, using a data warehouse can be difficult and complex at the same time.


Comparison between Data Warehouse and Data Mart:

	Data Warehouse	Data Mart
Definition	Removing informational processing load from transaction-oriented databases.	Data Mart can be considered as a subset of data warehouse. It is generally focused on a single functional area.
Focus	Multiple subject areas	Specific subject area
Control	Central organization unit	Generally, single department
Scope	Corporate	Line of Business
Data Sources	Multiple	Few selected
Size	100 GB-TB+	< 100 GB
Designing	Comparatively difficult	Easy
Advantages	It is accessible across the enterprise Contains historical and current data Can be considered as a "single version" of the truth about enterprise activities. Removes informational processing load from transaction-oriented databases	Incremental development Easy understanding of data Simple data design Easy Manipulation of data Better Reporting performance due to smaller queries
Implementation time	Months to years	Months
Decision	Strategic	Tactical