(maint) Elaborate on 8.1.0 release notes

documentation/release_notes_8.markdown

@@ -17,24 +17,44 @@ Released August 22 2023
 
 ## New features and improvements
 
-* Add el-9 as supported platform
-  [PDB-5667](https://perforce.atlassian.net/browse/PDB-5667)
+* RedHat Enterprise Linux 9 (RHEL 9) has been added as a supported
+  platform.
+  ([PDB-5667](https://perforce.atlassian.net/browse/PDB-5667))
 
-* Add ubuntu 22.04 as supported platform
-  [PDB-5636](https://perforce.atlassian.net/browse/PDB-5636)
+* Ubuntu 22.04 has been added as a supported platform.
+  ([PDB-5636](https://perforce.atlassian.net/browse/PDB-5636))
 
-* Abandon queries when client disconnects
-  [PDB-5645](https://perforce.atlassian.net/browse/PDB-5645)
+* PuppetDB will now abandon queries more promptly when a client
+  disconnects.  Previously an expensive query could continue running
+  indefinitely.  The same mechanism should also help ensure query
+  timeouts are immediately enforced.
+  ([GitHub #3867](https://github.com/puppetlabs/puppetdb/issues/3867))
 
-* PQL parsing of OR clauses can result in OOM errors
-  [PDB-5643](https://perforce.atlassian.net/browse/PDB-5643)
+* When no database migrations are pending, PuppetDB will no longer
+  disconnect clients on restart.
+  ([PE-36120](https://perforce.atlassian.net/browse/PE-36120))
 
-* Restarts of PuppetDB on the primary kill database connections on compilers when no migrations are pending
-  [PDB-36120](https://perforce.atlassian.net/browse/PDB-36120)
+### Bug fixes
+
+* Some PQL queries with numerous `or` clauses should no longer cause
+  PuppetDB to run out of memory.  Previously they could allocate an
+  exorbitant amount of RAM.
+  ([GitHub #3874](https://github.com/puppetlabs/puppetdb/issues/3874))
+
+### Known issues
+
+* The mechanism used to abandon queries and enforce timeouts mentioned
+  above may throw a `CancelledKeyException` when a network connection
+  is reused for multiple queries.  For the time being, the problem can
+  be addressed by setting the experimental environment variable
+  `PDB_PROMPTLY_END_QUERIES` to `false`.  (This variable may be
+  removed in a future release.)
+  ([GitHub #3866](https://github.com/puppetlabs/puppetdb/issues/3866))
 
 ### Contributors
 
-Austin Blatt, Nick Burgan-Illig, Jonathan Newman, Eric Newton, Joshua Partlow, Steve Axthelm, and Rob Browning
+Austin Blatt, Nick Burgan-Illig, Jonathan Newman, Eric Newton, Joshua
+Partlow, Steve Axthelm, and Rob Browning
 
 ## PuppetDB 8.0.1