Preview & Explain

Explains the difference between previewing the DSL query/pipeline before execution and requesting the actual MongoDB execution plan with explain.

preview()

preview() renders the current DSL into a diagnostic Document without executing the query on MongoDB. It is an API to check the build result, not the actual execution plan.

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• classic findAll, find, count, exists, distinct

• root aggregation()

• Atlas Search findAll/find/count/existsQuery

• Vector Search findAll/find/count/existsQuery

explain()

explain() executes the actual MongoDB Driver explain operation, so a database connection is required.

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You can pass ExplainVerbosity values like QUERY_PLANNER, EXECUTION_STATS, ALL_PLANS_EXECUTIONS directly from the Driver.

Used similarly in Search / Vector.

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