Store: improve index header reading performance by sorting labels

thanos-io · Aug 11, 2022 · 0aa5dda · 0aa5dda
1 parent 292dbb7
commit 0aa5dda
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/pkg/store/bucket.go b/pkg/store/bucket.go
@@ -1855,6 +1855,10 @@ func (r *bucketIndexReader) ExpandedPostings(ctx context.Context, ms []*labels.M
 		keys = append(keys, allPostingsLabel)
 	}
 
+	// Sort label name and value will improve the performance dramatically
+	// if the dataset is relatively large, since entries in postings offset table
+	// are sorted by label name and value, sequential reading is always faster.
+	sort.Sort(labels.Labels(keys))
 	fetchedPostings, err := r.fetchPostings(ctx, keys)
 	if err != nil {
 		return nil, errors.Wrap(err, "get postings")