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Learn what an aggregation pipeline is. |
An aggregation pipeline is similar to unix commands connected using pipes. We can construct modular, composable processing pipelines.
An aggregation pipeline consists of one or more stages that process documents:
Each stage performs an operation on the input documents. For example, a stage can filter documents, group documents, and calculate values.
The documents that are the output of a stage are passed as the input to the next stage.
An aggregation pipeline can return results for groups of documents. For example, return the total, average, maximum, and minimum values, etc.