has_deletions == false

[lockeliu]

hnswlib/hnswlib/hnswalg.h

Line 267 in 443d667

if ((-current_node_pair.first) > lowerBound && (top_candidates.size() == ef || has_deletions == false)) {

“ || has_deletions == false”

There is a problem with this judgment condition, which will cause the loop to exit early .

[dyashuni]

I think this is done intentionally. See #344

When has_deletions = true we have deleted elements and our recall is worse than we have no deleted elements. Therefore to improve the accuracy we add additional elements to the results if ((-current_node_pair.first) > lowerBound && (top_candidates.size() == ef)) to return ef elements.

[lockeliu]

I see.
But when has_deletions = false, how to ensure that the results are sufficient ?
when remove “ || has_deletions == false”, our results will be more.

[lockeliu]

"top_candidates.size() == ef "
This condition is essentially to solve the problem of less results.

[dyashuni]

As I understand when has_deletions = false we can not output less than ef elements (the only case when a total number of elements in the index is less than ef).

[lockeliu]

I see，thanks