Technical Evaluation - 101 - 2024

Which SQL function is used to count the number of rows in a SQL query?

• COUNT()
• NUMBER()
• SUM()
• COUNT(*)

Which of the following statement is true?

• DELETE does not free the space containing the table and TRUNCATE free the space containing the table
• Both DELETE and TRUNCATE free the space containing the table
• Both DELETE and TRUNCATE does not free the space containing the table
• DELETE free the space containing the table and TRUNCATE does not free the space containing the table

What is the purpose of the SQL AS clause?

• The AS SQL clause is used to change the name of a column in the result set or to assign a name to a derived column
• The AS clause is used with the JOIN clause only
• The AS clause defines a search condition
• All of the mentioned

_______ allow us to identify uniquely a tuple in the relation.

• schema
• superkey
• domain
• attribute

Which of the following is correct regarding Aggregate functions?

• it takes a single value and returns a single value as result
• it takes a list of values and return a single values as result
• it takes a list of values and return a list of values as result
• it takes a single value and returns a list of values as result

The attribute that can be divided into other attributes is called

• composite attribute
• derived attribute
• simple attribute
• multi-valued attribute

If every non-key attribute is functionally dependent on the primary key, the relation will be in

• fourth formal form
• third normal form
• first normal form
• second normal form

Database locking concept is used to solve the problem of

• inconsistent data
• lost update
• uncommitted dependency
• all of the options

A type of query that is placed within a WHERE or HAVING clause of another query is called

• multi-query
• sub query
• super query
• master query

If a piece of data is stored in two places in the database, then

• in can be more easily accessed
• both storage space is wasted and changing the data in one spot will cause data inconsistency
• storage space is wasted
• changing the data in one spot will cause data inconsistency