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。该信息包括从性能架构events_transactions_current和events_statements_history表派生的当前事务及其已执行的语句。（必须启用这些表的使用者以获取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。

参量

• in_thread_id BIGINT UNSIGNED：要为其返回交易信息的线程ID。该值应与THREAD_ID某些“性能模式”threads表行中的列匹配。

配置选项

ps_thread_trx_info()可以使用以下配置选项或其相应的用户定义变量来修改该操作（请参见“ sys_config表”）：

• 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。

返回值

一个LONGTEXT值。

例

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
      }
    ]
  }
]