DOCS-15997 planCacheSize Parameter SBE (#3254) (#3281)

* DOCS-15997 planCacheSize Parameter SBE

* JA feedback

* DS feedback

* DS feedback + move to 6.3 release notes

Author: ajhuh-mdb

source/reference/parameters.txt

@@ -5028,17 +5028,21 @@ Slot-Based Execution Parameters
 
 .. parameter:: planCacheSize
 
-   .. versionadded:: 5.1
+   .. versionadded:: 6.3
 
    *Type*: string
 
    *Default*: 5%
 
    |mongod-only|
 
-   Sets the size of the :ref:`plan cache
-   <read-operations-query-optimization>` for the slot based query
-   execution engine.
+   .. note:: 
+
+      Although the ``planCacheSize`` parameter existed in prior versions of 
+      MongoDB, it had no effect on the plan cache until version 6.3.
+
+   Sets the size of the :ref:`plan cache <read-operations-query-optimization>` 
+   only for the :ref:`slot-based query execution engine <5.1-rel-notes-sbe>`.
 
    You can set the :parameter:`planCacheSize` value to either:
 

source/release-notes/5.1.txt

@@ -150,15 +150,6 @@ new fields are included in the query explain plan output.
 - If the new query execution engine is used, new fields are included in
   the :ref:`query explain plan output <explain-results-5.1-later>`.
 
-Set Slot-Based Query Execution Plan Cache Size
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-You can set the size of the :ref:`plan cache
-<read-operations-query-optimization>` for the new query engine with the
-:parameter:`planCacheSize` parameter.
-
-.. include:: /includes/fact-sbe-plan-cache-motivation.rst
-
 .. _5.1-rel-notes-change-streams:
 
 Change Streams

source/release-notes/6.3.txt

@@ -166,6 +166,8 @@ Starting in MongoDB 6.3, these server parameters were added:
   the establishment of slow server connections. 
 - :parameter:`chunkMigrationConcurrency` sets the number of threads on
   the source shard and the receiving shard for migrating chunks.
+- :parameter:`planCacheSize` sets the size of the :ref:`plan cache
+  <read-operations-query-optimization>` for the {+sbe+}.
 
 Time Series Collection Custom Bucketing Parameters
 --------------------------------------------------