Update HISTORY.md with the recent memtable trimming fixes

Summary: Pull Request resolved: https://github.com/facebook/rocksdb/pull/6194

Differential Revision: D19125292

Pulled By: ltamasi

fbshipit-source-id: d41aca2755ec4bec07feedd6b561e8d18606a931

diff --git a/HISTORY.md b/HISTORY.md
index d9cc3b3ae34083035a714f2898acca26a0f0ab26..3ea00675a67ca2d2e2d3706cd7d83cd58e1ee88a 100644 (file)
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,5 +1,7 @@
 # Rocksdb Change Log
-## Unreleased
+## 6.5.3 (1/10/2020)
+### Bug Fixes
+* Fixed two performance issues related to memtable history trimming. First, a new SuperVersion is now created only if some memtables were actually trimmed. Second, trimming is only scheduled if there is at least one flushed memtable that is kept in memory for the purposes of transaction conflict checking.
 
 ## 6.5.2 (11/15/2019)
 ### Bug Fixes