txn: fix the maximum value of a transaction from 10GB to 1 TiB

basic-features.md

@@ -143,7 +143,7 @@ You can try out TiDB features on [TiDB Playground](https://play.tidbcloud.com/?u
 |---|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|:---:|
 | [Async commit](/system-variables.md#tidb_enable_async_commit-new-in-v50) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
 | [1PC](/system-variables.md#tidb_enable_1pc-new-in-v50) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
-| [Large transactions (10GB)](/transaction-overview.md#transaction-size-limit) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
+| [Large transactions (1 TiB)](/transaction-overview.md#transaction-size-limit) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
 | [Pessimistic transactions](/pessimistic-transaction.md) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
 | [Optimistic transactions](/optimistic-transaction.md) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |
 | [Repeatable-read isolation (snapshot isolation)](/transaction-isolation-levels.md) | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y | Y |

develop/dev-guide-transaction-restraints.md

@@ -709,8 +709,15 @@ mysql> SELECT * FROM T2;
 
 The basic principle is to limit the size of the transaction. At the KV level, TiDB has a restriction on the size of a single transaction. At the SQL level, one row of data is mapped to one KV entry, and each additional index will add one KV entry. The restriction is as follows at the SQL level:
 
-- The maximum single row record size is `120 MB`. You can adjust it by using the `performance.txn-entry-size-limit` configuration parameter of tidb-server for TiDB v4.0.10 and later v4.0.x versions, TiDB v5.0.0 and later versions. The value is `6 MB` for versions earlier than v4.0.10.
-- The maximum single transaction size supported is `10 GB`. You can configure it by `performance.txn-total-size-limit` for TiDB v4.0 and later versions. The value is `100 MB` for earlier versions.
+- The maximum single row record size is 120 MiB.
+
+    - You can adjust it by using the [`performance.txn-entry-size-limit`](/tidb-configuration-file.md#txn-entry-size-limit-new-in-v4010-and-v500) configuration parameter of tidb-server for TiDB v4.0.10 and later v4.0.x versions, TiDB v5.0.0 and later versions. The value is `6 MB` for versions earlier than v4.0.10.
+    - Starting from v7.6.0, you can use the [`tidb_txn_entry_size_limit`](/system-variables.md#tidb_txn_entry_size_limit-introduced-from-v760-version) system variable to dynamically modify the value of this configuration item.
+
+- The maximum single transaction size supported is 1 TiB. 
+
+    - You can configure it by [`performance.txn-total-size-limit`](/tidb-configuration-file.md#txn-total-size-limit) for TiDB v4.0 and later versions. The value is `100 MB` for earlier versions.
+    - In TiDB v6.5.0 and later versions, this configuration is no longer recommended. For more information, see [`performance.txn-total-size-limit`](/tidb-configuration-file.md#txn-total-size-limit).
 
 Note that for both the size restrictions and row restrictions, you should also consider the overhead of encoding and additional keys for the transaction during the transaction execution. To achieve optimal performance, it is recommended to write one transaction every 100 ~ 500 rows.
 

tidb-configuration-file.md

@@ -523,6 +523,7 @@ Configuration items related to performance.
 - In TiDB v6.5.0 and later versions, this configuration is no longer recommended. The memory size of a transaction will be accumulated into the memory usage of the session, and the [`tidb_mem_quota_query`](/system-variables.md#tidb_mem_quota_query) variable will take effect when the session memory threshold is exceeded. To be compatible with previous versions, this configuration works as follows when you upgrade from an earlier version to TiDB v6.5.0 or later:
     - If this configuration is not set or is set to the default value (`104857600`), after an upgrade, the memory size of a transaction will be accumulated into the memory usage of the session, and the `tidb_mem_quota_query` variable will take effect.
     - If this configuration is not defaulted (`104857600`), it still takes effect and its behavior on controlling the size of a single transaction remains unchanged before and after the upgrade. This means that the memory size of the transaction is not controlled by the `tidb_mem_quota_query` variable.
+- When TiDB executes transactions in the [`tidb_dml_type`](/system-variables.md#tidb_dml_type-new-in-v800) `"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).
 
 ### `tcp-keep-alive`