Question

1.6. Discuss the capabilities that should be provided by a DBMS.

1.7. Discuss the differences between database systems and information retrieval systems.

Answer 1

1.6 Discuss the capabilities that should be provided by a DBMS:-

Answer:-A DBMS should be equipped with the following capabilities :-

1.A DBMS should provide a secure and survivable medium for the storage of data.-The primary concern of today's era,where there are multiple raising layers of threat to user's data privacy,it becomes very pivotal that a good database management system should provide a safe and secure platform for the storage of data so that the data stored in the database is not compromised at any point.

2.A database management system should be able to self describe all its features:- A database management system should contain a complete description of database's structure and all the constrains defined in it.This data about data should be stored in a system catalog,which contains a description of the structure of each file,the type and storage format of each field,and the various constraints on the data.

3.DBMS provides Insulation between Programs and Data;Data abstraction:-In traditional file processing system,the structure of the data files accessed by an application is hard-coded in it's source code.If we change the structure of the data,every application in which a description of that file's structure is hard-coded must be changed.However,in contrast,the DBMS provides a conceptual or logical view of the data to the application programs,so the underlying implementation may be changed without the actual program being modified.

4.DBMS should provide multiple views of the data:-Different users have different views or perspective on the database.For example in an educational organization,say a college, an account department will not have access to the faculty data including anything about which courses he taught.

5.DBMS provides data-sharing and multi-user transaction processing feature:-Several users can update the same data in controlled manner so that the results of the updates are as though they were done in some sequential manner.This gives rise to the concept of transaction,which is a process that makes one or more accesses to a database and which must have the appearance of executing in isolation from all other transactions and being atomic.

6.Data Storage, Retrieval & Update of data:- The DBMS software allows the app to read data from the database, add new data into the database, modify the data or delete the data from the database.

7.DBMS provides Integrity Constraints:-Data is stored in relational databases in TABLES. Often, the data in one table is related to the data in another table. For example,consider an online purchase websites of products,the database may store customer data in one table, and a history of each of his/her purchase transaction in another table. The DBMS software can ensure that every purchase transaction ties back to a valid customer and, for example, prevent the insertion of a purchase transaction for a customer that is not on file. This is an example of the DBMS software enforcing a data integrity constraint.

8.DBMS,generally provides a QUERY language for following tasks:-Most of the database management software comes with a query language which helps in the insertion,deletion,updation and retrieval of data.Here queries are written to carry out all these operations and thus,providing a way to interact with the database.

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1.7 Discuss the differences between database systems and information retrieval systems:-

Answer:-Information retrieval system:
In raw layman's term the information retrieval system can be viewed similar to a normal google or a bing search.We search for some piece of information and the intended data is fetched from the respective web servers.Then,we select or choose only the important data or information which serves our purpose and leave out the rest of the search results.The term information retrieval was coined in 1952 and gained popularity from 1961 onwards. At that time,the information retrieval’s function was seen as a major advance in libraries that were no longer just storehouses of books, but also places where the information was catalogued and indexed.(which basically means that there were index or catalogues,which contained the address where the original information was stored).These system understand natural language,for example,a simple english sentence or a phrase.

Definition:
According to Harter,information retrieval system "is a device interposed between a potential user of information and information collection itself for a given information problem and the purpose of the system is to capture wanted items and to filter out unwanted items".
The concept of information retrieval system is to some extent is self explanatory from its term.One may simply denote such a system as one that stores and retrieves information.
The three major areas that constitute an information retrieval system are:
1. A large collection of information.
2. Users' queries (generally consist of natural language )
3. Matching of these queries with the documented or stored database.
Advantages of Information retrieval system:-

---->Provides the option of natural language search which is suitable for all users.

----->It is very scalable can index many billions of documents.

Disadvantages of Information retrieval system:-

-----> Less “reliable” along some dimensions than DBMS.

----->Only stores textual data and don't provide any specific query based approach to make things more efficient as in DBMS.

----->The data is present in an unstructured manner.
Database Management System:
A database management system is a collection of interrelated data and set of programs to access that data.It enables you to store, modify and extract information from a database.A database management system is a computer program designed to manage a database and run operations on the data requested by numerous clients. DBMSs have more recently emerged as a fairly standard part of any company back office.DBMSs are found at the heart of most database application sometimes.Queries are used to extract and modify data as per the needs of the organization.

A database application is computer software written to manage the data of a particular application or problem.In database management system, data can be retrieved in three levels.
1. Physical level:-It is the lowest level of data abstraction that describes how the data is actually stored.
2. Logical level:-It is the next higher level of data abstraction in DBMS which describes what data are stored in the database and what sort of relationships exist between them.
3. View level:-It is the highest level of data abstraction which describes only part of the entire database.We can think it to be similar to a user interface or a front-end version of a website or an application.The users included in this view won't be able to access the entire database but only a part of it in the form of a user interface.

Advantages of DBMS:-

------>It is reliable and secure.

-------->provides a query language for manipulation of data.

-------->Require skills(in SQL) in framing an actual database.

--------->Supports multiple views of the data and provide the feature of parallel transactions.

Disadvantages of DBMS:-

--------->It suffers from scaling limitations and hence can hold smaller size of data as compared to information retrieval system.

---------->It functions only by accepting queries in SQL and there's no support for natural language texts as was the case in information retrieval system.

Differences between Database management system and Information Retrieval System:-

1.The database management system provides an advanced Data Modelling Facility(DMF) including Data Definiton Language (DDL)and Data Manipulation Language(DML) for modelling and manipulating data.

However, IRSs do not offer an advance DMF. Usually data modelling in IRS is restricted to classification of objects.

2. Data Definiton Language of DBMS allows to define various data integrity constraints,which helps in developing or defining relationships between different data.
In IRSs such validation mechanisms are less developed and this accounts for its unstructured data form.

3. DBMSs provides precise semantics.
IRSs most of the time,provides imprecise semantics.

4. DBMSs has structured data format.
Wereas, IRSs is characterised by unstructured data format.

5. Query specification is complete in DBMS.
In IRS query specification is incomplete.

6. Query language is artificial in DBMS.
In IRS query language is near to natural language.

7.DBMS helps to get an exact match for our queries. In IR, more generally one is satisfied with the partial match and then select best one among the selected items.

8.DBMS offers various advanced features and is widely used in enterprises and organizations whereas IRS are not as popular in developing a database in such organizations or firms.