What are the comparative use cases of an IOManager vs a FileManager

In Dagster, the concept of an

IOManager

is distinct from that of a

FileManager

, and they serve different purposes within the system. An

IOManager

is a Dagster object that controls how data is read from and written to external systems or storage. It manages both inputs and outputs of ops and assets. For outputs, the

IOManager

handles writing the data to a configured location, and for inputs, it handles reading the data from storage so that it can be used by downstream ops or assets.

IOManagers

are particularly useful when you want to abstract away the details of how and where data is stored, making it easier to change storage solutions without modifying business logic. The documentation provides examples of how to define and use custom

IOManagers

to handle data storage and retrieval, such as reading and writing CSV files to the filesystem. It also mentions that

IOManagers

can be configured to handle partitioned assets, where each partition corresponds to a file or a range of rows in a database. On the other hand,

FileManager

is not a term that is explicitly defined in the provided documentation. However, in general software development terms, a file manager might refer to a utility or service that deals with file operations such as reading, writing, moving, and deleting files on a filesystem. It is not a Dagster-specific concept and would not have the same level of integration with Dagster's execution model as an

IOManager

. In summary, within the context of Dagster, you would use an

IOManager

to manage the storage and retrieval of data for ops and assets, abstracting away the details of the underlying storage mechanism. A file manager, while not specifically defined in the documentation, would typically be a more general-purpose tool for file operations and would not be integrated with Dagster's execution model or concepts like assets and partitions.