Description

Querying incremental segments that are being created during streaming ingestion is slower as rows are scanned sequentially. There exists an undocumented feature to skip these segments for query by passing a flag "skipIncrementalSegment" in the query context.

Query context has a documented flag for the query mode on real time segments called "realtimeSegmentsMode" and supports a few modes already. Adding a new mode to skip the incremental segments.

Key changed/added classes in this PR

processing/src/main/java/org/apache/druid/query/QueryContexts.java
server/src/main/java/org/apache/druid/client/CachingClusteredClient.java
server/src/main/java/org/apache/druid/segment/realtime/appenderator/SinkQuerySegmentWalker.java

This PR has:

• [x ] been self-reviewed.
  • using the concurrency checklist (Remove this item if the PR doesn't have any relation to concurrency.)
• added documentation for new or modified features or behaviors.
• a release note entry in the PR description.
• added Javadocs for most classes and all non-trivial methods. Linked related entities via Javadoc links.
• added or updated version, license, or notice information in licenses.yaml
• added comments explaining the "why" and the intent of the code wherever would not be obvious for an unfamiliar reader.
• added unit tests or modified existing tests to cover new code paths, ensuring the threshold for code coverage is met.
• added integration tests.
• been tested in a test Druid cluster.