Document that txn-total-size-limit won't affect pipelined dml (#18271)

system-variables.md

@@ -1830,6 +1830,7 @@ mysql> SELECT job_info FROM mysql.analyze_jobs ORDER BY end_time DESC LIMIT 1;
         - `"bulk"` mode cannot be used on tables containing foreign keys and tables referenced by foreign keys when the foreign key constraint check is enabled (`foreign_key_checks = ON`).
         - In situations that the environment does not support or is incompatible with the `"bulk"` mode, TiDB falls back to the `"standard"` mode and returns a warning message. To verify if the `"bulk"` mode is used, you can check the `pipelined` field using [`tidb_last_txn_info`](#tidb_last_txn_info-new-in-v409). A `true` value indicates that the `"bulk"` mode is used.
         - When executing large transactions in the `"bulk"` mode, the transaction duration might be long. For transactions in this mode, the maximum TTL of the transaction lock is the greater value between [`max-txn-ttl`](https://docs.pingcap.com/tidb/stable/tidb-configuration-file#max-txn-ttl) and 24 hours. Additionally, if the transaction execution time exceeds the value set by [`tidb_gc_max_wait_time`](#tidb_gc_max_wait_time-new-in-v610), the GC might force a rollback of the transaction, leading to its failure.
+        - When TiDB executes transactions in the `"bulk"` mode, transaction size is not limited by the TiDB configuration item [`txn-total-size-limit`](https://docs.pingcap.com/tidb/stable/tidb-configuration-file#txn-total-size-limit).
         - This mode is implemented by the Pipelined DML feature. For detailed design and GitHub issues, see [Pipelined DML](https://github.com/pingcap/tidb/blob/master/docs/design/2024-01-09-pipelined-DML.md) and [#50215](https://github.com/pingcap/tidb/issues/50215).
 
 ### tidb_enable_1pc <span class="version-mark">New in v5.0</span>