This is an automated cherry-pick of pingcap#6298

Signed-off-by: ti-chi-bot <ti-community-prow-bot@tidb.io>

system-variables.md

@@ -285,9 +285,18 @@ Constraint checking is always performed in place for pessimistic transactions (d
 
 ### tidb_enable_cascades_planner
 
+> **Warning:**
+>
+> Currently, cascades planner is an experimental feature. It is not recommended that you use it in the production environment.
+
 - Scope: SESSION | GLOBAL
+<<<<<<< HEAD
 - Default value: 0
 - This variable is used to control whether to enable the cascades planner, which is currently considered experimental.
+=======
+- Default value: `OFF`
+- This variable is used to control whether to enable the cascades planner.
+>>>>>>> 810499e09 (system variables.md: add a warning message (#6298))
 
 ### tidb_enable_chunk_rpc <span class="version-mark">New in v4.0</span>
 
@@ -297,6 +306,10 @@ Constraint checking is always performed in place for pessimistic transactions (d
 
 ### tidb_enable_fast_analyze
 
+> **Warning:**
+>
+> Currently, `Fast Analyze` is an experimental feature. It is not recommended that you use it in the production environment.
+
 - Scope: SESSION | GLOBAL
 - Default value: 0, indicating not enabling the statistics fast `Analyze` feature.
 - This variable is used to set whether to enable the statistics `Fast Analyze` feature.