diff --git a/statement-summary-tables.md b/statement-summary-tables.md
index a67732c0f8a9b..fce7390e15a5c 100644
--- a/statement-summary-tables.md
+++ b/statement-summary-tables.md
@@ -131,13 +131,6 @@ After the configuration above takes effect, every 30 minutes the `statements_sum
 
 The `statements_summary_evicted` table records the recent 24 periods during which SQL statements are evicted from the statement summary. The `statements_summary_evicted` table is updated every 30 minutes.
 
-The system variables above have two scopes: global and session. These scopes work differently from other system variables:
-
-- After setting the global variable, your setting applies to the whole cluster immediately.
-- After setting the session variable, your setting applies to the current TiDB server immediately. This is useful when you debug on a single TiDB server instance.
-- The session variable has a higher read priority. The global variable is read only when no session variable is set.
-- If you set the session variable to a blank string, the global variable is re-read.
-
 > **Note:**
 >
 > The `tidb_stmt_summary_history_size`, `tidb_stmt_summary_max_stmt_count`, and `tidb_stmt_summary_max_sql_length` configuration items affect memory usage. It is recommended that you adjust these configurations based on your needs. It is not recommended to set them too large values.