Speed up docvalues set query by making use of sortedness #12128
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LongHashSet is used for the set of numbers, but it has some issues: * tries to hard to extend AbstractSet, mostly for testing * causes traps with boxing if you aren't careful * complex hashcode/equals Practically we should take advantage of the fact numbers come in sorted order for multivalued fields: just like range queries do. So we use min/max to our advantage, including termination of docvalues iteration Actually it is generally a win to just check min/max even in the single-valued case: these constant time comparisons are cheap and can avoid hashing, etc. In the worst-case, if all of your query Sets contain both the minimum and maximum possible values, then it won't help, but it doesn't hurt either.
gsmiller
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Feb 5, 2023
asfgit
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Feb 6, 2023
LongHashSet is used for the set of numbers, but it has some issues: * tries to hard to extend AbstractSet, mostly for testing * causes traps with boxing if you aren't careful * complex hashcode/equals Practically we should take advantage of the fact numbers come in sorted order for multivalued fields: just like range queries do. So we use min/max to our advantage, including termination of docvalues iteration Actually it is generally a win to just check min/max even in the single-valued case: these constant time comparisons are cheap and can avoid hashing, etc. In the worst-case, if all of your query Sets contain both the minimum and maximum possible values, then it won't help, but it doesn't hurt either.
This was referenced Feb 6, 2023
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LongHashSet is used for the set of numbers, but it has some issues:
Practically we should take advantage of the fact numbers come in sorted order for multivalued fields: just like range queries do. So we use min/max to our advantage, including termination of docvalues iteration.
Actually it is generally a win to just check min/max even in the single-valued case: these constant time comparisons are cheap and can avoid hashing, etc.
In the worst-case, if all of your query Sets contain both the minimum and maximum possible values, then it won't help, but it doesn't hurt either.