remove a sentence that is under discussion

tiflash/tiflash-results-materialization.md

@@ -68,7 +68,7 @@ SELECT app_name, country FROM t1;
 
 <CustomContent platform="tidb-cloud">
 
-* The TiDB memory limit on the `INSERT INTO SELECT` statement can be adjusted using the system variable [`tidb_mem_quota_query`](/system-variables.md#tidb_mem_quota_query). The recommended memory usage of this statement is within 100 MiB. Starting from v6.5.0, it is not recommended to use [`txn-total-size-limit`](https://docs.pingcap.com/tidb/stable/tidb-configuration-file#txn-total-size-limit) to control transaction memory size.
+* The TiDB memory limit on the `INSERT INTO SELECT` statement can be adjusted using the system variable [`tidb_mem_quota_query`](/system-variables.md#tidb_mem_quota_query). Starting from v6.5.0, it is not recommended to use [`txn-total-size-limit`](https://docs.pingcap.com/tidb/stable/tidb-configuration-file#txn-total-size-limit) to control transaction memory size.
 
     For more information, see [TiDB memory control](https://docs.pingcap.com/tidb/stable/configure-memory-usage).