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Use _doc + _shard_doc as sort tiebreaker to get better performance #4569

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Merged
penghuo merged 2 commits into from
Oct 15, 2025
Merged

Use _doc + _shard_doc as sort tiebreaker to get better performance #4569

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7e6da58
Use _shard_doc as sort tiebreaker
LantaoJin Oct 15, 2025
18456f5
_doc as a part of tie-breaker have better performance
LantaoJin Oct 15, 2025
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27 changes: 20 additions & 7 deletions opensearch/src/main/java/org/opensearch/sql/opensearch/request/OpenSearchQueryRequest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,6 @@
import static org.opensearch.core.xcontent.DeprecationHandler.IGNORE_DEPRECATIONS;
import static org.opensearch.search.sort.FieldSortBuilder.DOC_FIELD_NAME;
import static org.opensearch.search.sort.SortOrder.ASC;
import static org.opensearch.sql.opensearch.storage.OpenSearchIndex.METADATA_FIELD_ID;

import java.io.IOException;
import java.util.Collections;
Expand All @@ -31,6 +30,9 @@
import org.opensearch.search.SearchModule;
import org.opensearch.search.builder.PointInTimeBuilder;
import org.opensearch.search.builder.SearchSourceBuilder;
import org.opensearch.search.sort.FieldSortBuilder;
import org.opensearch.search.sort.ShardDocSortBuilder;
import org.opensearch.search.sort.SortBuilders;
import org.opensearch.sql.opensearch.data.value.OpenSearchExprValueFactory;
import org.opensearch.sql.opensearch.response.OpenSearchResponse;
import org.opensearch.sql.opensearch.storage.OpenSearchIndex;
Expand All @@ -51,7 +53,7 @@ public class OpenSearchQueryRequest implements OpenSearchRequest {
private final IndexName indexName;

/** Search request source builder. */
private SearchSourceBuilder sourceBuilder;
private final SearchSourceBuilder sourceBuilder;

/** OpenSearchExprValueFactory. */
@EqualsAndHashCode.Exclude @ToString.Exclude
Expand Down Expand Up @@ -203,12 +205,23 @@ public OpenSearchResponse searchWithPIT(Function<SearchRequest, SearchResponse>
if (searchAfter != null) {
this.sourceBuilder.searchAfter(searchAfter);
}
// Set sort field for search_after
if (this.sourceBuilder.sorts() == null) {
// Add sort tiebreaker for PIT search.
// We cannot remove it since `_shard_doc` is not added implicitly in PIT now.
// Ref https://github.com/opensearch-project/OpenSearch/pull/18924#issuecomment-3342365950
if (this.sourceBuilder.sorts() == null || this.sourceBuilder.sorts().isEmpty()) {
// If no sort field specified, sort by `_doc` + `_shard_doc`to get better performance
this.sourceBuilder.sort(DOC_FIELD_NAME, ASC);
// Workaround to preserve sort location more exactly,
// see https://github.com/opensearch-project/sql/pull/3061
this.sourceBuilder.sort(METADATA_FIELD_ID, ASC);
this.sourceBuilder.sort(SortBuilders.shardDocSort());
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@Swiddis Swiddis Oct 15, 2025 •
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Does it matter if we duplicate fields in the sorting list? We could simplify/remove the below else logic by just always appending this, I would expect Lucene to optimize it in the background but I haven't measured it.

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@LantaoJin LantaoJin Oct 15, 2025

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not sure will Lucene optimize duplicated fields or _doc in sorting, but for sure the duplicated _shard_doc is not allowed in OpenSearch Core. It is no harmful for restricted checker here.

} else {
// If sort fields specified, sort by `fields` + `_doc` + `_shard_doc`.
if (this.sourceBuilder.sorts().stream()
.noneMatch(
b -> b instanceof FieldSortBuilder f && f.fieldName().equals(DOC_FIELD_NAME))) {
this.sourceBuilder.sort(DOC_FIELD_NAME, ASC);
}
if (this.sourceBuilder.sorts().stream().noneMatch(ShardDocSortBuilder.class::isInstance)) {
this.sourceBuilder.sort(SortBuilders.shardDocSort());
}
}
SearchRequest searchRequest =
new SearchRequest().indices(indexName.getIndexNames()).source(this.sourceBuilder);
Expand Down
3 changes: 0 additions & 3 deletions ...earch/src/test/java/org/opensearch/sql/opensearch/request/OpenSearchQueryRequestTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -184,7 +184,6 @@ void search_with_pit() {
when(searchResponse.getHits()).thenReturn(searchHits);
when(searchHits.getHits()).thenReturn(new SearchHit[] {searchHit});
when(searchHit.getSortValues()).thenReturn(new String[] {"sortedValue"});
when(sourceBuilder.sorts()).thenReturn(null);

OpenSearchResponse openSearchResponse = request.searchWithPIT(searchAction);
assertFalse(openSearchResponse.isEmpty());
Expand Down Expand Up @@ -215,7 +214,6 @@ void search_with_pit_hits_null() {
when(searchAction.apply(any())).thenReturn(searchResponse);
when(searchResponse.getHits()).thenReturn(searchHits);
when(searchHits.getHits()).thenReturn(new SearchHit[] {searchHit});
when(sourceBuilder.sorts()).thenReturn(null);

OpenSearchResponse openSearchResponse = request.searchWithPIT(searchAction);
assertFalse(openSearchResponse.isEmpty());
Expand All @@ -237,7 +235,6 @@ void search_with_pit_hits_empty() {
when(searchAction.apply(any())).thenReturn(searchResponse);
when(searchResponse.getHits()).thenReturn(searchHits);
when(searchHits.getHits()).thenReturn(new SearchHit[] {});
when(sourceBuilder.sorts()).thenReturn(null);

OpenSearchResponse openSearchResponse = request.searchWithPIT(searchAction);
assertTrue(openSearchResponse.isEmpty());
Expand Down
9 changes: 4 additions & 5 deletions ...rch/src/test/java/org/opensearch/sql/opensearch/request/OpenSearchRequestBuilderTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -13,7 +13,6 @@
import static org.opensearch.search.sort.SortOrder.ASC;
import static org.opensearch.sql.data.type.ExprCoreType.INTEGER;
import static org.opensearch.sql.data.type.ExprCoreType.STRING;
import static org.opensearch.sql.opensearch.storage.OpenSearchIndex.METADATA_FIELD_ID;

import java.util.Collections;
import java.util.List;
Expand Down Expand Up @@ -408,7 +407,7 @@ void test_push_down_project() {
.size(MAX_RESULT_WINDOW)
.timeout(DEFAULT_QUERY_TIMEOUT)
.sort(DOC_FIELD_NAME, ASC)
.sort(METADATA_FIELD_ID, ASC)
.sort(SortBuilders.shardDocSort())
.pointInTimeBuilder(new PointInTimeBuilder("samplePITId"))
.fetchSource(new String[] {"intA"}, new String[0]),
requestBuilder);
Expand All @@ -421,7 +420,7 @@ void test_push_down_project() {
.size(MAX_RESULT_WINDOW)
.timeout(DEFAULT_QUERY_TIMEOUT)
.sort(DOC_FIELD_NAME, ASC)
.sort(METADATA_FIELD_ID, ASC)
.sort(SortBuilders.shardDocSort())
.pointInTimeBuilder(new PointInTimeBuilder("samplePITId"))
.fetchSource("intA", null),
exprValueFactory,
Expand Down Expand Up @@ -536,7 +535,7 @@ void test_push_down_project_with_alias_type() {
.size(MAX_RESULT_WINDOW)
.timeout(DEFAULT_QUERY_TIMEOUT)
.sort(DOC_FIELD_NAME, ASC)
.sort(METADATA_FIELD_ID, ASC)
.sort(SortBuilders.shardDocSort())
.pointInTimeBuilder(new PointInTimeBuilder("samplePITId"))
.fetchSource(new String[] {"intA"}, new String[0]),
requestBuilder);
Expand All @@ -549,7 +548,7 @@ void test_push_down_project_with_alias_type() {
.size(MAX_RESULT_WINDOW)
.timeout(DEFAULT_QUERY_TIMEOUT)
.sort(DOC_FIELD_NAME, ASC)
.sort(METADATA_FIELD_ID, ASC)
.sort(SortBuilders.shardDocSort())
.pointInTimeBuilder(new PointInTimeBuilder("samplePITId"))
.fetchSource("intA", null),
exprValueFactory,
Expand Down
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