Explain the following terms: a) Atomicity b) Data Manipulation Language (DML)

a) Atomicity: Atomicity is a concept from database systems and is one of the four primary characteristics of a transaction, commonly known by the acronym ACID (Atomicity, Consistency, Isolation, Durability). It refers to transactions being indivisible and irreducible. This means that in the context of a database modification, a transaction must either be completed in its entirety or not executed at all. If any part of the transaction fails, the entire transaction fails and the database state is left unchanged. It ensures that the database remains in a consistent state by preventing partial updates to the database which could lead to data corruption.

b) DML: DML stands for Data Manipulation Language, which is a subset of SQL (Structured Query Language) used for adding (inserting), deleting, and modifying (updating) data in a database. DML is the language that allows users to work with the data in a database, actually doing things like adding new records, removing records, or updating records. The operations provided by DML are not to be confused with the operations provided by another subset of SQL called DDL (Data Definition Language); DML statements are used to manipulate the data itself, while DDL statements are used to define and modify the database structure.

Atomicity in context with other ACID properties: - Consistency ensures that the database changes states upon a committed transaction and that the data follows all validation rules. - Isolation dictates the concurrency control of transactions, ensuring that transactions occurring at the same time do not affect each other's execution. - Durability guarantees that once a transaction has been committed, it remains so, even in the case of a system failure.

Atomicity can be thought of like a promise that when you tell a database to perform a series of actions, it will either do all of them or none of them. If you're buying something online, atomicity ensures that both the payment and the update to the store's inventory happen together – if there is an issue with one of them, neither action should occur.

DML in the context of SQL: SQL is a language designed specifically for managing data stored in a relational database management system (RDBMS). The main types of SQL commands are:

- DML (Data Manipulation Language): It includes commands like INSERT (to add new rows of data), UPDATE (to modify existing data), and DELETE (to remove data). - DDL (Data Definition Language): It includes commands like CREATE TABLE, ALTER TABLE, and DROP TABLE, which define or alter the structure of the database. - DCL (Data Control Language): It includes commands like GRANT and REVOKE, which manage rights and permissions to the database system. - TCL (Transaction Control Language): It includes commands like COMMIT and ROLLBACK, which manage the different transactions occurring within a database