What will come in place of the question mark (?) in the

Which of the following ACID properties ensures that either all operations within a transaction are completed successfully, or none are?

Which constraint ensures that a column contains only unique values, but allows NULL values?

Query optimization heuristics often include:

During transaction before commit which of the following statements is done automatically in case of shutdown?

Indexes improve query performance but can degrade performance of:

The 'thrashing' in an operating system is related to:

Which property of a transaction ensures that either all operations within the transaction are completed successfully, or none of them are?

In a relational database, what is a candidate key?

In a relational database, which relationship allows multiple records in one table to be associated with multiple records in another table?