early cut off for order by sub agg in term agg

This commit is contained in:
Pascal Seitz
2026-04-27 17:13:39 +02:00
committed by PSeitz
parent c11952eb7c
commit d47abdf104
12 changed files with 514 additions and 25 deletions
@@ -199,6 +199,17 @@ impl SegmentAggregationCollector for SegmentCompositeCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// Composite is a multi-bucket agg with no single value to extract.
None
}
}
impl SegmentCompositeCollector {
+11
View File
@@ -674,6 +674,17 @@ impl<B: SubAggBuffer> SegmentAggregationCollector for SegmentFilterCollector<B>
}
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// TODO: forward into the inner `sub_agg` for nested order paths (`filter.metric`).
None
}
}
/// Intermediate result for filter aggregation
@@ -394,6 +394,17 @@ impl SegmentAggregationCollector for SegmentHistogramCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// Histogram is a multi-bucket agg with no single value to extract.
None
}
}
impl SegmentHistogramCollector {
+11
View File
@@ -328,6 +328,17 @@ impl<B: SubAggBuffer> SegmentAggregationCollector for SegmentRangeCollector<B> {
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// Range is a multi-bucket agg with no single value to extract.
None
}
}
/// Build a concrete `SegmentRangeCollector` with either a Vec- or HashMap-backed
/// bucket storage, depending on the column type and aggregation level.
+310 -25
View File
@@ -352,19 +352,15 @@ pub(crate) fn build_segment_term_collector(
)));
}
// Validate sub aggregation exists when ordering by sub-aggregation.
{
if let OrderTarget::SubAggregation(sub_agg_name) = &terms_req_data.req.order.target {
let (agg_name, _agg_property) = get_agg_name_and_property(sub_agg_name);
node.get_sub_agg(agg_name, &req_data.per_request)
.ok_or_else(|| {
TantivyError::InvalidArgument(format!(
"could not find aggregation with name {agg_name} in metric \
sub_aggregations"
))
})?;
}
// Validate that the referenced sub-aggregation exists when ordering by one.
if let OrderTarget::SubAggregation(sub_agg_name) = &terms_req_data.req.order.target {
let (agg_name, _agg_property) = get_agg_name_and_property(sub_agg_name);
node.get_sub_agg(agg_name, &req_data.per_request)
.ok_or_else(|| {
TantivyError::InvalidArgument(format!(
"could not find aggregation with name {agg_name} in metric sub_aggregations"
))
})?;
}
// Build sub-aggregation blueprint if there are children.
@@ -887,6 +883,17 @@ impl<TermMap: TermAggregationMap, B: SubAggBuffer> SegmentAggregationCollector
}
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// Terms is a multi-bucket agg with no single value to extract.
None
}
}
/// Missing value are represented as a sentinel value in the column.
@@ -960,9 +967,6 @@ where
) -> crate::Result<IntermediateBucketResult> {
let mut entries: Vec<(u64, Bucket)> = term_buckets.into_vec();
let order_by_sub_aggregation =
matches!(term_req.req.order.target, OrderTarget::SubAggregation(_));
match &term_req.req.order.target {
OrderTarget::Key => {
// We rely on the fact, that term ordinals match the order of the strings
@@ -974,10 +978,37 @@ where
entries.sort_unstable_by_key(|bucket| bucket.0);
}
}
OrderTarget::SubAggregation(_name) => {
// don't sort and cut off since it's hard to make assumptions on the quality of the
// results when cutting off du to unknown nature of the sub_aggregation (possible
// to check).
OrderTarget::SubAggregation(sub_agg_path) => {
// Peek segment-level metric values, sort, then fall through to
// `cut_off_buckets`. Like Elasticsearch, we always cut off when ordering
// by a sub-agg: top-K results are approximate and may differ from the
// global ordering, especially for non-monotonic metrics like avg/min.
let coll = sub_agg_collector.as_deref().ok_or_else(|| {
TantivyError::InvalidArgument(format!(
"Could not find sub-aggregation collector for path {sub_agg_path}"
))
})?;
let (agg_name, agg_prop) = get_agg_name_and_property(sub_agg_path);
// Fetch values up-front; otherwise sort would re-compute per comparison
let mut keyed: Vec<(f64, (u64, Bucket))> = entries
.into_iter()
.map(|bucket| {
let metric_value = coll
.compute_metric_value(bucket.1.bucket_id, agg_name, agg_prop, agg_data)
.unwrap_or(0.0);
(metric_value, bucket)
})
.collect();
if term_req.req.order.order == Order::Desc {
keyed.sort_unstable_by(|a, b| {
b.0.partial_cmp(&a.0).unwrap_or(std::cmp::Ordering::Equal)
});
} else {
keyed.sort_unstable_by(|a, b| {
a.0.partial_cmp(&b.0).unwrap_or(std::cmp::Ordering::Equal)
});
}
entries = keyed.into_iter().map(|(_, e)| e).collect();
}
OrderTarget::Count => {
if term_req.req.order.order == Order::Desc {
@@ -988,11 +1019,8 @@ where
}
}
let (term_doc_count_before_cutoff, sum_other_doc_count) = if order_by_sub_aggregation {
(0, 0)
} else {
cut_off_buckets(&mut entries, term_req.req.segment_size as usize)
};
let (term_doc_count_before_cutoff, sum_other_doc_count) =
cut_off_buckets(&mut entries, term_req.req.segment_size as usize);
let mut dict: FxHashMap<IntermediateKey, IntermediateTermBucketEntry> = Default::default();
dict.reserve(entries.len());
@@ -1767,6 +1795,263 @@ mod tests {
Ok(())
}
#[test]
fn terms_aggregation_order_by_cardinality_desc_single_segment() -> crate::Result<()> {
terms_aggregation_order_by_cardinality_desc(true)
}
#[test]
fn terms_aggregation_order_by_cardinality_desc_multi_segment() -> crate::Result<()> {
terms_aggregation_order_by_cardinality_desc(false)
}
fn terms_aggregation_order_by_cardinality_desc(merge_segments: bool) -> crate::Result<()> {
// Distinct score values per bucket key: A→5, B→1, C→3.
// Order by cardinality desc must yield A, C, B.
let segment_and_terms = vec![vec![
(1.0, "A".to_string()),
(2.0, "A".to_string()),
(3.0, "A".to_string()),
(4.0, "A".to_string()),
(5.0, "A".to_string()),
(1.0, "B".to_string()),
(1.0, "B".to_string()),
(1.0, "B".to_string()),
(1.0, "C".to_string()),
(2.0, "C".to_string()),
(3.0, "C".to_string()),
]];
let index = get_test_index_from_values_and_terms(merge_segments, &segment_and_terms)?;
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "card": "desc" }
},
"aggs": {
"card": { "cardinality": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][0]["card"]["value"], 5.0);
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][1]["card"]["value"], 3.0);
assert_eq!(res["my_texts"]["buckets"][2]["key"], "B");
assert_eq!(res["my_texts"]["buckets"][2]["card"]["value"], 1.0);
// Asc engages the segment-cutoff path too (monotonic-safe: discarded buckets had
// local card >= cutoff, so merged card >= cutoff and they cannot be globally smallest).
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "card": "asc" }
},
"aggs": {
"card": { "cardinality": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "B");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][2]["key"], "A");
// size=2 with desc engages the segment cutoff: must keep top-2 by cardinality (A, C),
// and `sum_other_doc_count` reflects the dropped B (3 docs).
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"size": 2,
"order": { "card": "desc" }
},
"aggs": {
"card": { "cardinality": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"].as_array().unwrap().len(), 2);
// size=2 with asc engages the segment cutoff: must keep bottom-2 by cardinality (B, C).
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"size": 2,
"order": { "card": "asc" }
},
"aggs": {
"card": { "cardinality": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "B");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"].as_array().unwrap().len(), 2);
Ok(())
}
#[test]
fn terms_aggregation_order_by_sum_single_segment() -> crate::Result<()> {
terms_aggregation_order_by_sum(true)
}
#[test]
fn terms_aggregation_order_by_sum_multi_segment() -> crate::Result<()> {
terms_aggregation_order_by_sum(false)
}
fn terms_aggregation_order_by_sum(merge_segments: bool) -> crate::Result<()> {
// Per-bucket sums on the U64 `score` column (non-negative => sum is monotonic):
// A → 1+2+3+4+5 = 15, B → 1+1+1 = 3, C → 1+2+3 = 6.
let segment_and_terms = vec![
vec![
(1.0, "A".to_string()),
(2.0, "A".to_string()),
(3.0, "A".to_string()),
(1.0, "B".to_string()),
(1.0, "C".to_string()),
],
vec![
(4.0, "A".to_string()),
(5.0, "A".to_string()),
(1.0, "B".to_string()),
(1.0, "B".to_string()),
(2.0, "C".to_string()),
(3.0, "C".to_string()),
],
];
let index = get_test_index_from_values_and_terms(merge_segments, &segment_and_terms)?;
// Desc on a Sum metric engages the fast path (column is U64).
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "total": "desc" }
},
"aggs": {
"total": { "sum": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][0]["total"]["value"], 15.0);
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][1]["total"]["value"], 6.0);
assert_eq!(res["my_texts"]["buckets"][2]["key"], "B");
assert_eq!(res["my_texts"]["buckets"][2]["total"]["value"], 3.0);
// Asc engages the fast path too — discarded buckets had local sum >= cutoff,
// and merged sum >= local (non-negative addends), so they cannot be globally smallest.
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "total": "asc" }
},
"aggs": {
"total": { "sum": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "B");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][2]["key"], "A");
// size=2 desc with cutoff: top-2 by sum (A, C).
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"size": 2,
"order": { "total": "desc" }
},
"aggs": {
"total": { "sum": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"].as_array().unwrap().len(), 2);
// Stats sub-property: ordering by `mystats.sum` on a U64 column also engages.
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "mystats.sum": "desc" }
},
"aggs": {
"mystats": { "stats": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][2]["key"], "B");
// Sum on a signed column (I64) takes the same cutoff path. Results may be
// approximate near the boundary on adversarial data, but for this dataset the
// top-K is unambiguous.
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "total": "desc" }
},
"aggs": {
"total": { "sum": { "field": "score_i64" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][2]["key"], "B");
// Order by extended_stats sub-property exercises compute_metric_value on the
// ExtendedStats collector. A→max=5, B→max=1, C→max=3, so desc by max → A, C, B.
let agg_req: Aggregations = serde_json::from_value(json!({
"my_texts": {
"terms": {
"field": "string_id",
"order": { "ext.max": "desc" }
},
"aggs": {
"ext": { "extended_stats": { "field": "score" } }
}
}
}))
.unwrap();
let res = exec_request(agg_req, &index)?;
assert_eq!(res["my_texts"]["buckets"][0]["key"], "A");
assert_eq!(res["my_texts"]["buckets"][1]["key"], "C");
assert_eq!(res["my_texts"]["buckets"][2]["key"], "B");
Ok(())
}
#[test]
fn terms_aggregation_test_order_key_single_segment() -> crate::Result<()> {
terms_aggregation_test_order_key_merge_segment(true)
@@ -177,6 +177,17 @@ impl SegmentAggregationCollector for TermMissingAgg {
}
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// TODO: forward to `sub_agg` for nested order paths (`missing_agg>metric`).
None
}
}
#[cfg(test)]
+22
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@@ -445,6 +445,28 @@ impl SegmentAggregationCollector for SegmentCardinalityCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
let req_data = &agg_data.get_cardinality_req_data(self.accessor_idx);
if req_data.name != sub_agg_name || !sub_agg_property.is_empty() {
return None;
}
let bucket = self.buckets.get(bucket_id as usize)?.as_ref()?;
// For string columns the HLL sketch is empty until materialization; entries holds
// the deduplicated term ordinals seen, which is the exact distinct count.
// For numeric columns the sketch is populated during collect.
if self.column_type == ColumnType::Str {
Some(bucket.entries.len() as f64)
} else {
Some(bucket.cardinality.sketch.estimate().trunc())
}
}
}
#[derive(Clone, Debug)]
+20
View File
@@ -399,6 +399,26 @@ impl SegmentAggregationCollector for SegmentExtendedStatsCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
if self.name != sub_agg_name {
return None;
}
let extended = self.buckets.get(bucket_id as usize)?;
// Finalize is a pure read of accumulators — calling it here for the cutoff sort
// doesn't disturb the eventual intermediate result.
extended
.finalize()
.get_value(sub_agg_property)
.ok()
.flatten()
}
}
#[cfg(test)]
+20
View File
@@ -312,6 +312,26 @@ impl SegmentAggregationCollector for SegmentPercentilesCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
if agg_data.get_metric_req_data(self.accessor_idx).name != sub_agg_name {
return None;
}
let percentile: f64 = sub_agg_property.parse().ok()?;
if !(0.0..=100.0).contains(&percentile) {
return None;
}
let bucket = self.buckets.get(bucket_id as usize)?;
// DDSketch.quantile is a pure read; calling it here for the cutoff sort does
// not affect the intermediate state used for the final result.
bucket.sketch.quantile(percentile / 100.0).ok().flatten()
}
}
#[cfg(test)]
+34
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@@ -321,6 +321,40 @@ impl<const COLUMN_TYPE_ID: u8> SegmentAggregationCollector
}
Ok(())
}
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
if self.name != sub_agg_name {
return None;
}
let stats = self.buckets.get(bucket_id as usize)?;
// The property depends on what we're collecting:
// - StatsType::Stats exposes count/sum/min/max/avg via dotted property.
// - Single-value kinds (Sum/Count/Min/Max/Average) expect an empty property and return
// the value they were configured to collect.
let prop = match self.collecting_for {
StatsType::Stats if !sub_agg_property.is_empty() => sub_agg_property,
StatsType::Sum if sub_agg_property.is_empty() => "sum",
StatsType::Count if sub_agg_property.is_empty() => "count",
StatsType::Max if sub_agg_property.is_empty() => "max",
StatsType::Min if sub_agg_property.is_empty() => "min",
StatsType::Average if sub_agg_property.is_empty() => "avg",
_ => return None,
};
match prop {
"count" => Some(stats.count as f64),
"sum" => Some(stats.sum),
"min" if stats.count > 0 => Some(stats.min),
"max" if stats.count > 0 => Some(stats.max),
"avg" if stats.count > 0 => Some(stats.sum / stats.count as f64),
_ => None,
}
}
}
#[inline]
+11
View File
@@ -644,6 +644,17 @@ impl SegmentAggregationCollector for TopHitsSegmentCollector {
);
Ok(())
}
fn compute_metric_value(
&self,
_bucket_id: BucketId,
_sub_agg_name: &str,
_sub_agg_property: &str,
_agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
// top_hits is not a numeric metric and cannot be used as an order target.
None
}
}
#[cfg(test)]
+42
View File
@@ -76,6 +76,31 @@ pub trait SegmentAggregationCollector: Debug {
fn flush(&mut self, _agg_data: &mut AggregationsSegmentCtx) -> crate::Result<()> {
Ok(())
}
/// Compute the segment-level metric value of the named direct-child metric for `bucket_id`.
///
/// Used by parent term aggs that order by a sub-aggregation: the parent sorts on
/// this value and cuts off at segment time, matching the approximation tradeoff
/// Elasticsearch makes for any sub-agg ordering.
///
/// `sub_agg_property` is the dotted suffix (e.g. `"sum"` in `mystats.sum`); empty when
/// the metric is a single-value kind such as cardinality.
///
/// Returns `None` only on name mismatch, unknown property, or empty bucket. Implementations
/// may finalize their per-bucket state (e.g. compute a percentile from a sketch); calls
/// must be idempotent so the final intermediate result is unaffected.
///
/// No default impl on purpose: every collector must decide explicitly whether it
/// produces a metric value, forwards into children (single-bucket aggs), or rejects
/// the lookup. A silent `None` default would let a parent term agg's cutoff sort all
/// buckets to the same key and drop arbitrary winners.
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
agg_data: &AggregationsSegmentCtx,
) -> Option<f64>;
}
#[derive(Default)]
@@ -137,4 +162,21 @@ impl SegmentAggregationCollector for GenericSegmentAggregationResultsCollector {
}
Ok(())
}
fn compute_metric_value(
&self,
bucket_id: BucketId,
sub_agg_name: &str,
sub_agg_property: &str,
agg_data: &AggregationsSegmentCtx,
) -> Option<f64> {
for agg in &self.aggs {
if let Some(value) =
agg.compute_metric_value(bucket_id, sub_agg_name, sub_agg_property, agg_data)
{
return Some(value);
}
}
None
}
}