advancedN+1 Queries & Fetching Strategies — JOIN FETCH, Entity Graph, Batch Fetch
Why is combining JOIN FETCH with pagination on a one-to-many association a well-known trap?
The JOIN multiplies result rows — one row per child — so applying a LIMIT/pagination to the raw SQL result doesn't correctly limit the number of DISTINCT parent entities; it can cut off partway through a parent's children or produce an incorrect page size, since the database has no concept that multiple rows belong to the same logical parent.
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