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Select operation in SQL is equivalent to
- a)the selection operation in relational algebra
- b)the selection operation in relational algebra, except that select in SQL retains duplicates
- c)the projection operation in relational algebra
- d)the projection operation in relational algebra, except that select in SQL retains duplicates
Correct answer is option 'D'. Can you explain this answer?
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Select operation in SQL is equivalent toa)the selection operation in r...
Select operation is equivalent to the projection operation in relational algebra, except that select in SQL retains duplicates and on the contrary projection removes the duplicates.
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Select operation in SQL is equivalent toa)the selection operation in r...
Introduction
In SQL (Structured Query Language), the SELECT operation is used to retrieve data from a database table. It is equivalent to the selection operation in relational algebra, which is a theoretical framework for working with relational databases. However, there is a difference between the two operations when it comes to handling duplicates.
Selection Operation in Relational Algebra
The selection operation in relational algebra allows us to select rows from a table that satisfy a given condition. It is denoted by the sigma (σ) symbol. The condition is specified using predicates, such as equality (=), inequality (!=), greater than (>), less than (<), etc.="" the="" result="" of="" the="" selection="" operation="" is="" a="" new="" table="" that="" contains="" only="" the="" rows="" that="" meet="" the="" specified="">
Selection Operation in SQL
In SQL, the SELECT statement is used to retrieve data from one or more tables. It allows us to specify the columns we want to retrieve and the conditions that must be satisfied by the rows. The SELECT statement includes the SELECT, FROM, WHERE, and optional ORDER BY clauses. The WHERE clause is used to specify the condition for selecting rows.
Difference in Handling Duplicates
The main difference between the selection operation in relational algebra and SQL is the handling of duplicates. In relational algebra, the selection operation eliminates duplicates from the result, whereas in SQL, the SELECT operation retains duplicates by default.
This means that if the selection operation in relational algebra produces duplicate rows, they are eliminated in the result. On the other hand, if the SELECT operation in SQL produces duplicate rows, they are included in the result.
Projection Operation in Relational Algebra
The projection operation in relational algebra is used to select specific columns from a table. It is denoted by the pi (π) symbol. The result of the projection operation is a new table that contains only the selected columns.
Conclusion
In summary, the SELECT operation in SQL is equivalent to the selection operation in relational algebra. However, the SELECT operation in SQL retains duplicates by default, whereas the selection operation in relational algebra eliminates duplicates. Therefore, the correct answer is option D - the SELECT operation in SQL is equivalent to the projection operation in relational algebra, except that SELECT in SQL retains duplicates.
In SQL (Structured Query Language), the SELECT operation is used to retrieve data from a database table. It is equivalent to the selection operation in relational algebra, which is a theoretical framework for working with relational databases. However, there is a difference between the two operations when it comes to handling duplicates.
Selection Operation in Relational Algebra
The selection operation in relational algebra allows us to select rows from a table that satisfy a given condition. It is denoted by the sigma (σ) symbol. The condition is specified using predicates, such as equality (=), inequality (!=), greater than (>), less than (<), etc.="" the="" result="" of="" the="" selection="" operation="" is="" a="" new="" table="" that="" contains="" only="" the="" rows="" that="" meet="" the="" specified="">
Selection Operation in SQL
In SQL, the SELECT statement is used to retrieve data from one or more tables. It allows us to specify the columns we want to retrieve and the conditions that must be satisfied by the rows. The SELECT statement includes the SELECT, FROM, WHERE, and optional ORDER BY clauses. The WHERE clause is used to specify the condition for selecting rows.
Difference in Handling Duplicates
The main difference between the selection operation in relational algebra and SQL is the handling of duplicates. In relational algebra, the selection operation eliminates duplicates from the result, whereas in SQL, the SELECT operation retains duplicates by default.
This means that if the selection operation in relational algebra produces duplicate rows, they are eliminated in the result. On the other hand, if the SELECT operation in SQL produces duplicate rows, they are included in the result.
Projection Operation in Relational Algebra
The projection operation in relational algebra is used to select specific columns from a table. It is denoted by the pi (π) symbol. The result of the projection operation is a new table that contains only the selected columns.
Conclusion
In summary, the SELECT operation in SQL is equivalent to the selection operation in relational algebra. However, the SELECT operation in SQL retains duplicates by default, whereas the selection operation in relational algebra eliminates duplicates. Therefore, the correct answer is option D - the SELECT operation in SQL is equivalent to the projection operation in relational algebra, except that SELECT in SQL retains duplicates.
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Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer?
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Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer?.
Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? for Computer Science Engineering (CSE) 2024 is part of Computer Science Engineering (CSE) preparation. The Question and answers have been prepared according to the Computer Science Engineering (CSE) exam syllabus. Information about Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? covers all topics & solutions for Computer Science Engineering (CSE) 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer?.
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Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer?, a detailed solution for Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? has been provided alongside types of Select operation in SQL is equivalent toa)the selection operation in relational algebrab)the selection operation in relational algebra, except that select in SQL retains duplicatesc)the projection operation in relational algebrad)the projection operation in relational algebra, except that select in SQL retains duplicatesCorrect answer is option 'D'. Can you explain this answer? theory, EduRev gives you an
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