DMSEndtermQuestion

Which of the following statements is true regarding PostgreSQL VIEWs?

• VIEWs can be used to simplify complex queries and provide a layer of abstraction.

• VIEWs can only be created on a single table.

• VIEWs can contain INSERT, UPDATE, and DELETE statements

• VIEWs are always updatable by default

What window function incorporates the count of rows with the same value into the rank of the tied rows, resulting in non-sequential ranks

• RANK()

• CUME_DIST()

• ROW_NUMBER()

• PERCENT_RANK()

Which of the following is an aggregate function?

• LEFT()

• COUNT()

• LENGTH()

• UPPER()

What is Atomicity in the context of ACID properties?

• Ensuring that a transaction is treated as a single unit, which is either fully completed or fully rolled back

• Ensuring that a transaction is divided into multiple smaller transactions

• Ensuring that the transaction results are permanently stored in the database

• Ensuring that the database can handle multiple transactions concurrently

What does the CUBE keyword do in conjunction with GROUP BY?

• It creates a grouping set that includes all possible combinations of columns

• It filters the result set based on a specific condition.

• It assumes a hierarchy among the input columns and generates all grouping sets that make sense considering the hierarchy

• All of the above

Which clause is used to define a window for window functions?

• WHERE

• OVER

• WINDOW

• GROUP BY

Which window function is used to return the same rank for the rows which have the same values?

• DENSE_RANK()

• PERCENT_RANK()

• NTILE()

• CUME_DIST()

Which type of index would you create to ensure that all values in a column are unique?

• B-tree index

• Partial index

• Unique index

• Hash index

Which PostgreSQL statement is used to create an INDEX?

• ADD INDEX

• CREATE INDEX

• ALTER INDEX

• MAKE INDEX

Can Triggers in PostgreSQL be used to modify the triggering operation itself?

• Yes, Triggers can modify the triggering operation as well as the underlying data.

• No, Triggers can only modify the data affected by the triggering operation.

• No, Triggers cannot modify the triggering operation

• Yes, but only if the transaction is explicitly rolled back