Elasticsearch 6.0 introduces a new feature called Index Sorting, which optimizes the storage of documents on disk by ordering them in a user-specified manner. This enhancement, originating from Lucene's IndexSorter tool, allows for significant improvements in query performance through a mechanism known as "early termination," where queries can be short-circuited after retrieving a specified number of sorted documents. Historically, Lucene's static sorting tool was replaced with a dynamic merge policy that allows sorting during the merge process, but Elasticsearch now allows sorting at flush time to enhance efficiency further. While this feature can greatly benefit search response times, especially with large datasets, it comes with a trade-off of reduced indexing performance due to the additional overhead of sorting. The decision to implement Index Sorting should, therefore, carefully consider the balance between write and query performance. Practical examples include creating efficient leaderboard queries for gaming applications by sorting documents based on player scores. However, if optimized for write performance, this feature might not be suitable due to its potential to decrease write throughput by up to 50%. Testing with specific use cases and datasets is crucial to determine its effectiveness.