updated release notes

Author: hmottestad

site/content/release-notes/5.2.0.md

@@ -4,6 +4,21 @@ toc: true
 ---
 RDF4J 5.2.0 is a minor release that fixes 9 issues.
 
+### Highlights
+*	Explain plans over HTTP. You can now request EXPLAIN via the REST API, making it easier to diagnose and tune slow SPARQL queries.
+*	SPARQL queries using MINUS and OPTIONAL clauses are significantly faster.
+*  Performance improvements to the LMDB Store, reducing query time by an average of 50% and reducing overhead for concurrent queries.
+*	Configurable LMDB GC. A new valueEvictionInterval lets you tune (or disable) LMDB value‑cache garbage collection to balance latency vs. memory.
+
+### Other improvements
+*	Higher bulk‑ingest throughput for Sails that build on AbstractSailConnection thanks to an experimental bulk‑add hook.
+*	SPARQL UPDATE operations now show up in the query/update logs.
+
+### Bug fixes
+*	Geospatial accuracy (Lucene). Filters like ehContains now correctly exclude geometries outside the requested area when a resource has multiple shapes.
+*	Namespace operations on unknown repositories now return 404 instead of 500.
+*	The SPARQL parser now rejects invalid CONSTRUCT templates that contain property paths, with a clear error.
+
 For a complete overview, see [all issues fixed in 5.2.0](https://github.com/eclipse/rdf4j/milestone/115?closed=1).
 
 ### Acknowledgements