> ## Documentation Index
> Fetch the complete documentation index at: https://doc.lucidworks.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Fusion AI 4.2.1 Release Notes

[localhost link]: http://localhost:3000/docs/4/fusion-ai/release-notes/4.2.1-release-notes

[mintlify link]: https://doc.lucidworks.com/docs/4/fusion-ai/release-notes/4.2.1-release-notes

[old doc.lw link]: https://doc.lucidworks.com/fusion-ai/4.2/433

**Release date:** 5 April 2019

**Component versions:**

|          |                  |             |                        |              |
| -------- | ---------------- | ----------- | ---------------------- | ------------ |
| Solr 7.5 | ZooKeeper 3.4.13 | Spark 2.3.2 | Jetty 9.4.12.v20180830 | Ignite 2.6.0 |

**More information about support dates can be found at [Lucidworks Fusion Product Lifecycle](/docs/policies/lifecycle-policies/lw-fusion-product-lifecycle).**

## New features

No new features were introduced in Fusion AI 4.2.1.

See the [Fusion Server 4.2.1 release notes](/docs/4/fusion-server/release-notes/4.2.1-release-notes) for other changes.

## Improvements

* In the `_user_query_history_aggregation` SQL aggregation job, the default value of the `signalTypeWeights` SQL parameter has been changed from `click:1.0,add-to-cart:10.0,purchase:25.0` to `request:1.0,click:5.0,cart:10.0,purchase:25.0` to add request signals so that all signal types are included in these aggregations.

* Query Rewriting UI improvements:

  * Facet groups can now be collapsed and expanded for easier viewing.
  * Query rewrites are now faceted by tag.
  * The **Apply Rules** query pipeline stage has a new parameter, **Partially Matched Filter Queries Will Trigger the Rule**/`matchPartialFilterQueries`, which allows a rule to fire when it is configured with multiple **Field Value** conditions and only some of those conditions are matched.
  * The **Misspelling Detection** page now has a **Published** column.

* Manually-created query rewrites are now automatically assigned a review value of "Approved" and the **Review** field is no longer editable in the query rewrite creation interface.

* Fixed an issue which broken rules with banner actions when the **Banner Zone** field value was an integer.

* Better checks for duplicate rewrites.

* Uni-directional synonyms are now working correctly in the `query_rewrite_staging` collection and the Simulator.

* A manually-created head/tail query improvement now has its `action` field correctly populated.

  * A variety of minor UI issues were fixed.