Pagination issue when using Semantic Search about meilisearch

[runabol]

Fair enough. Was able to work around this. Thanks!

[dureuill]

hello @runabol 👋

The effect you are seeing is caused by the search algorithm of the semantic search. The semantic search uses an Approximate Nearest-Neighbor (ANN) search algorithm to find the limit+offset vectors that are the "closest" to the query vector.
Because the algorithm is approximate, increasing limit+offset might result in "closer" vectors being found, which means that the order of results is not guaranteed to remain stable for two distinct values of limit+offset.
As it is a design characteristic of ANN algorithms, and exact algorithms (kNN) don't scale with the number and size of vectors, this behavior is unlikely to be fixed.
As a workaround, you can set offset to 0, set a large value for limit, and then apply the pagination manually in frontend.
In the future, we might consider some mitigation to this behavior, where we would always, for example, consider the first few hundred results (as if limit+offset would be equal to, say 1000) regardless of the actual value of limit+offset. There's a correctness/performance tradeoff to measure here, though.

Thank you for the report ❤️