Deduplicate min and max term in single-term FieldReader#13618
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original-brownbear merged 1 commit intoapache:mainfrom Jul 31, 2024
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I noticed that single-term readers are an edge case but not that uncommon in Elasticsearch heap dumps. It seems quite common to have a constant value for some field across a complete segment (e.g. a version value that is repeated endlessly in logs). Seems simple enough to deduplicate here to save a couple MB of heap.
jpountz
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It feels like a corner case, but the change is simple enough. LGTM.
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Thanks Adrien! |
original-brownbear
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Jul 31, 2024
I noticed that single-term readers are an edge case but not that uncommon in Elasticsearch heap dumps. It seems quite common to have a constant value for some field across a complete segment (e.g. a version value that is repeated endlessly in logs). Seems simple enough to deduplicate here to save a couple MB of heap.
original-brownbear
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Mar 10, 2025
Found this case in Elasticsearch heap dump's and it'as the same as apache#13618 but for BKDReader instances. Admittedly, as for terms this is a corner case but observed use cases where the distribution of these values is heavily weighted towards a single value would save up to a O(5M) in heap and some cache pressure from this change.
original-brownbear
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Mar 10, 2025
Found this case in Elasticsearch heap dump's and it'as the same as apache#13618 but for BKDReader instances. Admittedly, as for terms this is a corner case but observed use cases where the distribution of these values is heavily weighted towards a single value would save up to a O(5M) in heap and some cache pressure from this change.
original-brownbear
added a commit
that referenced
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Mar 10, 2025
Found this case in Elasticsearch heap dump's and it'as the same as #13618 but for BKDReader instances. Admittedly, as for terms this is a corner case but observed use cases where the distribution of these values is heavily weighted towards a single value would save up to a O(5M) in heap and some cache pressure from this change.
original-brownbear
added a commit
that referenced
this pull request
Mar 10, 2025
Found this case in Elasticsearch heap dump's and it'as the same as #13618 but for BKDReader instances. Admittedly, as for terms this is a corner case but observed use cases where the distribution of these values is heavily weighted towards a single value would save up to a O(5M) in heap and some cache pressure from this change.
hanbj
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Mar 12, 2025
Found this case in Elasticsearch heap dump's and it'as the same as apache#13618 but for BKDReader instances. Admittedly, as for terms this is a corner case but observed use cases where the distribution of these values is heavily weighted towards a single value would save up to a O(5M) in heap and some cache pressure from this change.
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I noticed that single-term readers are an edge case but not that uncommon in Elasticsearch heap dumps. It seems quite common to have a constant value for some field across a complete segment (e.g. a version value that is repeated endlessly in logs).
Seems simple enough to deduplicate here to save a couple MB of heap, though it's admittedly an edge case that mostly matters for large segment counts.