[Roadmap] 1.5.0 Roadmap

[trivialfis]

@dmlc/xgboost-committer Please add your items here by editing this post. Let's ensure that

• Each item has to be associated with a ticket
• Major design/refactoring are associated with a RFC before committing the code
• Blocking issue must be marked as blocking
• Breaking change must be marked as breaking

For other contributors who have no permission to edit the post, please comment here about what you think should be in 1.5.0.

• New external memory implementation using data iterator. (Export Python Interface for external memory. #7070)
• [JVM-Packages] Early stopping attributes ([XGBoost4J-Spark] Early stopping and best iteration #6893)
• Further development on categorical data support. (Categorical data support. #6503)
• [Python] Add min_delta to early stopping. (Add tolerance to early stopping. #6942, Support min_delta in early stopping. #7137)
• New R predict function.

[stevendavis]

+1 for Revising ranking objectives. #6450

[Shadyelgewily]

+1 for ([XGBoost4J-Spark] Early stopping and best iteration) #6893

[trivialfis]

• Add score tree interval to early stopping. (Add score tree interval #5238, [Feature Request] Add score_tree_interval during early stopping #5090)
• Improve ranking implementation. ([RFC] Revising ranking objectives. #6450)

Moving the 2 items to the next release. I will start planning the release before the end of next week.

[trivialfis]

Closing. The remaining packaging issues are tracked in #7260