c. Answer the following questions.
1. What is a database?
2. Distinguish between DBMS and RDBMS.
3. What are tuples and attributes?
4. Describe the primary key.
5. What is a composite key? Give an example.
Answers
Answer:
Ans 1. A database is a collection of information that is organized so that it can be easily accessed, managed and updated. Computer databases typically contain aggregations of data records or files, containing information about sales transactions or interactions with specific customers.
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Ans 2. DBMS:- 1. DBMS applications store data as file.
2. In DBMS, data is generally stored in either a hierarchical form or a navigational form.
3. Normalization is not present in DBMS. Normalization is present in RDBMS.
4) DBMS does not apply any security with regards to data manipulation.
5) DBMS uses file system to store data, so there will be no relation between the tables.
RDBMS:- 1. RDBMS applications store data in a tabular form.
2. In RDBMS, the tables have an identifier called primary key and the data values are stored in the form of tables.
3. Normalization is present in RDBMS.
4. RDBMS defines the integrity constraint for the purpose of ACID (Atomocity, Consistency, Isolation and Durability) property
5. in RDBMS, data values are stored in the form of tables, so a relationship between these data values will be stored in the form of a table as well.
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Ans 3. An attribute is a name paired with a domain (nowadays more commonly referred to as a type or data type). An attribute value is an attribute name paired with an element of that attribute's domain, and a tuple is a set of attribute values in which no two distinct elements have the same name
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Ans 4. A primary key is the column or columns that contain values that uniquely identify each row in a table. A database table must have a primary key for Optim to insert, update, restore, or delete data from a database table. Optim uses primary keys that are defined to the database.
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Ans 5. In database design, a composite key is a candidate key that consists of two or more attributes (table columns) that together uniquely identify an entity occurrence (table row). A compound key is a composite key for which each attribute that makes up the key is a simple (foreign) key in its own right.
Ex- (Example is in the image which will be easy for u to understand....)
