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MMWT-Database vinodsrivastava.wordpress.com DATABASE SYSTEMS 1. What is a DBMS? DBMS is the database system where data, tables, views and other database objects are stored as tables. Its full form is Database Management System. 2. What are the significances/advantages of a Database? The significances of a Database are:- 1. It reduces the redundancy of data. 2. It gives a distributed data management system. 3. It avoids the inconsistency of data. 4. It maintains the data integrity. 3. Give the full forms of the following abbreviations: 1. RDBMS 2. DBMD The full forms are:- 1. RDBMS: Relational Database Management System 2. DBMS: Database Management System 4. What are the Difference between Number and Auto Number Data type? Number Auto Number 1. The Auto Number data type is 1 . The Number data type can be used for used for storing only integer numbers. storing various kinds of numbers such as 2. These values are automatically generated integers, decimals etc. 2 . These values are input by the user when a record is added. 3. The Auto Number data type is used or unique sequential (incrementing by 1) 3. They need not be in sequence numbers DATABASE CONCEPT Q5 What are the Difference between Text and Memo Data type? Text Memo 1. Memo fields can store up to 1 gigabyte of 1. Text fields may store up to a maximum of 255 characters characters 2. Text Field can be Sort 2. Fields of memo data type cannot be grouped while filtering and it is not possible to sort them. Q6. Define the Following Terms Degree : The number of the columns or attributes in a table is called Degree. A attribute is also calledColumn. So, it is also a count of the attributes. Cardinality: The number of tuples in a table is called Cardinality. A tuple is also called Row. So, it is also a count of the rows. Q7 What are two the differences between Number and Date types? Two differences between Number and Date types are give below:- Number Date It allows to store any numeric values. It allows to store Date values. It can't hold more than 8 digits. It can store only number type values and It can store system date, containing date and does time not allow the character values. information. 8. What are two the different types of relations among the tables? Any two out of the following relations can exist between two tables: 1. One- To-One 2. One-To-Many 3. Many-To-Many 9. What are the three differences between Alternate and Foreign Keys? Three differences between Alternate and Foreign Keys are give below:- Alternate Foreign key It is a candidate keyk teyha t is not the primary It is key in table which is a primary key in key. another table. It is used to link the related It is one out of the set of candidate keys. tIta ibsl e.al ways s primary key for the first table. A key that can be used as a unique It does not uniquely identify the rows in the identifier for the table. record sets. 10. What are the two differences between Candidate and Primary Keys? Two differences between Candidate and Primary are give below:- Candidate Primary key The attributes or columKnsey of a table that can It is one or more than one attributes which serve can Iast ca thne't Pbecorimamrye Kae Fory. eign Key in another table. Iidet isn ttheify tchean duindiaqtuee f orre coa rFodsr einig an tKabeyle. in another table. MMWT-12 @ VKS-Learning Hub Page 2 DATABASE CONCEPT 11. What is importance of Primary Key? Explain with a suitable example. A Primary Key of relation identifies the unique records in the relation. The relation is also called Table. A Primary Key is a set of one or more than one attributes in a table.. A Primary Key column can't accept the duplicate values. Let's consider a table named CUSTOMER_DETAILS consists of the following attributes: 1. CUST_ID 2. BOB_ID 3. PAN_NUMBER 4. AADHAR_NUMBER 5. CUST_NAME Any one out of CUST_ID, BOD_UD , PAN_NUNBER and AADHAR_NUMBER can be used as the Primary Key and the remaining columns are called as Alternate Keys. 12. Write a short notes on DBMS. DBMS is a Software System that stores data in a tabular form. It is the software system that stores data, table, views and other database objects as tables. All system level information stored inside the special storage area and that is called Data Dictionary. Database Management System adds some significances and the important significances are: 1. It reduces the redundancy of data. 2. It gives a distributed data management system. 3. It avoids the inconsistency of data. 4. It maintains the data integrity. DBMS are provided by the product companies like Oracle and two example of FOSS DBMS are: 1. MySQL Database 2. Postgresql Database 13. Study the following-data and answer the questions given below : Table: BOOK_INVENTORY TITLE_ID TITLE AUTHOR PUB_YEAR MRP 2310201201 Revolution 2020 Chetan Bhagat 2011 140.00 2410201202 The Facebook Effect D. Kirkpatrickt 2010 399.00 2110201203 The Grand Design S Hawking 2010 499.00 2110201204 Wine Collin Gem 2009 320.00 Table: BOOK_SALES TITLE_ID ISBN_NO SALE_DATE DIS_PRICE 2310201201 978-81-291-1880-1 23/10/2012 120.00 2310201201 978-81-291-1880-2 24/10/2012 120.00 2110201203 978-81-291-1882-1 21/10/2010 450.00 2410201204 978-81-291-1883-1 12/10/2010 220.00 1. Name the field, which can act as the primary key for the table BOOK_INVENTORY and the table BOOK_SALES respectively. 2. Name the field, which can act as the foreign key for the table BOOK_SALES. 3. What kind of relations can exist between BOOK_INVENTORY and BOOK_SALES? TITLE_ID can act as Primary Key for BOOK_INVENTORY table. TITLE_ID is the Foreign Key for BOOK_SLAES table. Two types of relations can between them and they are:- 1. One-To-One 2. One-To-Many MMWT-12 @ VKS-Learning Hub Page 3 .
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