26.4.5.17 ps_thread_trx_info()函数

返回一个 JSON 对象，其中包含有关给定线程的信息。该信息包括从 Performance Schema events_transactions_current和events_statements_historytable 派生的当前事务及其已执行的语句。 (必须启用这些 table 的使用者以获取 JSON 对象中的完整数据.)

如果输出超出了截断长度(默认为 65535)，则返回 JSON 错误对象，例如：

{ "error": "Trx info truncated: Row 6 was cut by GROUP_CONCAT()" }

对于函数执行期间引发的其他警告和异常，将返回类似的错误对象。

Parameters

• in_thread_id BIGINT UNSIGNED：要为其返回 Transaction 信息的线程 ID。该值应与“性能模式threads”table 行中的THREAD_ID列匹配。

Configuration Options

可以使用以下配置选项或其相应的用户定义变量(请参见第 26.4.2.1 节“ sys_configtable”)来修改ps_thread_trx_info()操作：

• ps_thread_trx_info.max_length , @sys.ps_thread_trx_info.max_length

输出的最大长度。默认值为 65535.

Return Value

LONGTEXT值。

Example

mysql> SELECT sys.ps_thread_trx_info(48)\G
*************************** 1. row ***************************
sys.ps_thread_trx_info(48): [
  {
    "time": "790.70 us",
    "state": "COMMITTED",
    "mode": "READ WRITE",
    "autocommitted": "NO",
    "gtid": "AUTOMATIC",
    "isolation": "REPEATABLE READ",
    "statements_executed": [
      {
        "sql_text": "INSERT INTO info VALUES (1, \'foo\')",
        "time": "471.02 us",
        "schema": "trx",
        "rows_examined": 0,
        "rows_affected": 1,
        "rows_sent": 0,
        "tmp_tables": 0,
        "tmp_disk_tables": 0,
        "sort_rows": 0,
        "sort_merge_passes": 0
      },
      {
        "sql_text": "COMMIT",
        "time": "254.42 us",
        "schema": "trx",
        "rows_examined": 0,
        "rows_affected": 0,
        "rows_sent": 0,
        "tmp_tables": 0,
        "tmp_disk_tables": 0,
        "sort_rows": 0,
        "sort_merge_passes": 0
      }
    ]
  },
  {
    "time": "426.20 us",
    "state": "COMMITTED",
    "mode": "READ WRITE",
    "autocommitted": "NO",
    "gtid": "AUTOMATIC",
    "isolation": "REPEATABLE READ",
    "statements_executed": [
      {
        "sql_text": "INSERT INTO info VALUES (2, \'bar\')",
        "time": "107.33 us",
        "schema": "trx",
        "rows_examined": 0,
        "rows_affected": 1,
        "rows_sent": 0,
        "tmp_tables": 0,
        "tmp_disk_tables": 0,
        "sort_rows": 0,
        "sort_merge_passes": 0
      },
      {
        "sql_text": "COMMIT",
        "time": "213.23 us",
        "schema": "trx",
        "rows_examined": 0,
        "rows_affected": 0,
        "rows_sent": 0,
        "tmp_tables": 0,
        "tmp_disk_tables": 0,
        "sort_rows": 0,
        "sort_merge_passes": 0
      }
    ]
  }
]