Introduction:
A transaction in a database management system (DBMS) refers to a sequence of operations that are treated as a single unit. These operations can include reading, writing, and modifying data. Transactions ensure the integrity and consistency of data in a database. There are four fundamental properties of a transaction in a DBMS, namely atomicity, consistency, durability, and scalability. In this answer, we will explain these properties and why scalability is not considered a property of a transaction.

Atomicity:
Atomicity refers to the all-or-nothing property of a transaction. It ensures that either all the operations in a transaction are executed successfully, or none of them are. If any operation in a transaction fails, the entire transaction is rolled back, and the database returns to its previous state.

Consistency:
Consistency ensures that a transaction brings the database from one consistent state to another consistent state. It guarantees that the data remains valid and satisfies any predefined integrity constraints during the execution of a transaction. Consistency ensures that the database is not left in an intermediate or incomplete state.

Durability:
Durability guarantees that once a transaction is committed, its effects are permanent and will survive any subsequent failures, such as power outages or system crashes. The changes made by a committed transaction are stored in a way that can be recovered even if the system fails.

Scalability:
Scalability refers to the ability of a system to handle increasing amounts of work or data. It is the property that allows a system to handle a growing number of transactions, users, or data volume without a significant decrease in performance. Scalability is not considered a property of a transaction in a DBMS because it relates to the overall system architecture and design rather than the individual transactions themselves.

Conclusion:
In conclusion, scalability is not a property of a transaction in a DBMS. The properties of a transaction include atomicity, consistency, and durability. Atomicity ensures that a transaction is either fully executed or not executed at all. Consistency guarantees that a transaction brings the database from one consistent state to another. Durability ensures that the effects of a committed transaction are permanent. Scalability, on the other hand, refers to the ability of a system to handle increasing workloads and is not directly related to the properties of a transaction.