TRACE
The TRACE statement provides detailed information about query execution. It is intended to be viewed through a Graphical interface exposed by the TiDB server's status port.
Synopsis
TraceStmt:
TraceableStmt:
Examples
trace format='row' select * from mysql.user;
+--------------------------------------------+-----------------+------------+
| operation | startTS | duration |
+--------------------------------------------+-----------------+------------+
| trace | 17:03:31.938237 | 886.086µs |
| ├─session.Execute | 17:03:31.938247 | 507.812µs |
| │ ├─session.ParseSQL | 17:03:31.938254 | 22.504µs |
| │ ├─executor.Compile | 17:03:31.938321 | 278.931µs |
| │ │ └─session.getTxnFuture | 17:03:31.938337 | 1.515µs |
| │ └─session.runStmt | 17:03:31.938613 | 109.578µs |
| │ ├─TableReaderExecutor.Open | 17:03:31.938645 | 50.657µs |
| │ │ └─distsql.Select | 17:03:31.938666 | 21.066µs |
| │ │ └─RPCClient.SendRequest | 17:03:31.938799 | 158.411µs |
| │ └─session.CommitTxn | 17:03:31.938705 | 12.06µs |
| │ └─session.doCommitWitRetry | 17:03:31.938709 | 2.437µs |
| ├─*executor.TableReaderExecutor.Next | 17:03:31.938781 | 224.327µs |
| └─*executor.TableReaderExecutor.Next | 17:03:31.939019 | 6.266µs |
+--------------------------------------------+-----------------+------------+
13 rows in set (0.00 sec)
trace format='json' select * from mysql.user;
The JSON formatted trace can be pasted into the trace viewer, which is accessed via the TiDB status port:
MySQL compatibility
This statement is a TiDB extension to MySQL syntax.