0
Want this question answered?
Be notified when an answer is posted
Add your answer:
Earn +20 pts
Why does SQL allow duplicate tuples?
There are many reasons why SQL allows duplicate tuples (rows):To store non-unique values.To simply remove primary keys, unique indexes, and unique constraints.It allows this if there is no unique constraint.
Which construct in SQL is used to test whether a subquery has any tuples in its result?
Exists
What is tuples in sql?
Tuple is a collection of one or more attributes or rows present in a table.
How do you calculate the range in maths?
You calculate the range by subtracting the first and last number in the sequence
How do you calculate range?
Get the biggest number and take away the smaller number
Why duplicate tuples are not allowed in DBMS?
Since relation is a set, and tuples are element of a set, according to set theory, the elements of a set are not ordered.
Why selection query is first done than projection query?
Selection has more power to reduce size (Number of rows) while projection can not reduce number of tuples
What angle add up to 150?
How about 1 and 149. There are an infinite number of pairs, an infinite number of triplets, an infinite number of quadruplets, ... an infinite number of n-tuples. And n, itself, can be infinitely large.
Tuple in dbms?
rows are called tuples
What is a full outer join sql?
Join is used to combine related tuples from two relations . Full outer join cover all possible combinations of common tuples.
Why are tuples in a relation not ordered?
A relation is defined as a set of tuples. Mathematically, elements of a set have no order among them; hence, tuples in a relation do not have any particular order. In other words, a relation is not sensitive to the ordering of tuples. Tuple ordering is not part of a relation definition because a relation attempts to represent facts at a logical or abstract level. Many logical orders can be specified on a relation but there is no preference for one logical ordering over another.
Why the tuples in a relation are not ordered?
A relation is defined as a set of tuples. Mathematically, elements of a set have no order among them; hence, tuples in a relation do not have any particular order. In other words, a relation is not sensitive to the ordering of tuples. Tuple ordering is not part of a relation definition because a relation attempts to represent facts at a logical or abstract level. Many logical orders can be specified on a relation but there is no preference for one logical ordering over another.
How do you calculate the number of units sold?
How to calculate the number of units sold?
What do extension and intentions of relations mean in dbms?
ExtensionThe extension of a given relation is the set of tuples appearing in that relation at any given instance. The extension thus varies with time. It changes as tuples are created, destroyed, and updated.
What provides the ability to query information from the database and to insert tuples into delete tuples from and modify tuples in the database?
SQL (Structured Query Language) provides the ability to query, insert, delete, and modify data in a database. It is a standard language used for managing and manipulating relational databases. By using SQL commands, users can interact with the database to retrieve, add, change, or remove data as needed.
What is spurious tuples?
A spurious tuple is a record in database that get created when two tables are joined badly. Spurious tuples are created when two tables are joined on attributes that are neither primary keys nor foreign keys. Hopes this will help you .
Why does SQL allow duplicate tuples?
There are many reasons why SQL allows duplicate tuples (rows):To store non-unique values.To simply remove primary keys, unique indexes, and unique constraints.It allows this if there is no unique constraint.
