Make the HitQueue size more appropriate for KNN exact search #13184
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benwtrent
approved these changes
Mar 14, 2024
| @@ -98,7 +98,8 @@ protected TopDocs exactSearch(LeafReaderContext context, DocIdSetIterator accept | |||
| parentBitSet, | |||
| query, | |||
| fi.getVectorSimilarityFunction()); | |||
| HitQueue queue = new HitQueue(k, true); | |||
| final int queueSize = Math.min(k, Math.toIntExact(acceptIterator.cost())); | |||
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I don't know a better way, but, since this diversifies over parent doc ids, its possible that the hitqueue is still much smaller than acceptIterator.cost() as acceptIterator.cost() is the iterator over CHILD docs (e.g. passage vector docs). I think any further optimization (e.g. counting the number of relevant parents) would add undo overhead.
benwtrent
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Mar 19, 2024
Currently, when performing KNN exact search, we consistently set the HitQueue size to k. However, there may be instances where the number of candidates is actually lower than k.
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Description
Currently, when performing KNN exact search, we consistently set the HitQueue size to
k. However, there may be instances where the number of candidates is actually lower thank.