Airflow Operators and Hooks

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here is a brief explanation of them and use cases:

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• Operators are subclasses of the #BaseOperator, which is the base class for all Airflow operators.
• Operators define tasks that are executed as part of a workflow.
• Operators are instantiated and assigned to a dag object, which represents a workflow.
• Operators have an execute method that defines the logic of the task.
• Operators can be categorized into different types based on their functionality, such as action operators, transfer operators, sensor operators, etc.

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• Hooks are subclasses of the #BaseHook, which is the base class for all Airflow hooks.
• Hooks provide interfaces to connect to external systems or services.
• Hooks are instantiated and passed as arguments to operators or other functions, which use them to perform operations on external systems or services.
• Hooks have various methods that allow them to connect, interact, or disconnect with external systems or services.
• Hooks can be categorized into different types based on the external system or service they connect to, such as database hooks, cloud hooks, web hooks, etc.

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?? When we want to define a simple task that performs a single operation on an external system or service, such as running a SQL query on a database, copying a file to a cloud storage, sending an email notification, etc. In this case, we can use one of the built-in operators that Airflow provides for various external systems or services.

?? When we want to define a custom task that involves some logic or processing before or after performing an operation on an external system or service, such as validating data quality, applying transformations, generating reports, etc. In this case, we can create our own operator by subclassing the BaseOperator or one of its existing subclasses.

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?? When we want to perform multiple or complex operations on an external system or service within a single task, such as fetching data from multiple sources, performing bulk operations, executing transactions, etc. In this case, we can use one of the built-in hooks that Airflow provides for various external systems or services, or create our own hook by subclassing the BaseHook.

?? When we want to share data or state between tasks that interact with the same external system or service, such as passing query results, file names, connection objects, etc. In this case, we can use the #XCom mechanism that Airflow provides for cross-communication between tasks, and use hooks to push or pull data or state to or from XCom.