The display content of TiDB
SHOW PROCESSLIST is almost the same as that of MySQL
SHOW PROCESSLIST. TiDB
SHOW PROCESSLIST does not display the system process ID. The ID that it displays is the current session ID. The differences between TiDB
SHOW PROCESSLIST and MySQL
SHOW PROCESSLIST are as follows:
- As TiDB is a distributed database, the
tidb-serverinstance is a stateless engine for parsing and executing the SQL statements (for details, see TiDB architecture).
SHOW PROCESSLISTdisplays the session list executed in the
tidb-serverinstance that the user logs in to from the MySQL client, not the list of all the sessions running in the cluster. But MySQL is a standalone database and its
SHOW PROCESSLISTdisplays all the SQL statements executed in MySQL.
Statecolumn in TiDB is not continually updated during query execution. Because TiDB supports parallel query, each statement might be in multiple states at once, and so it is difficult to simplify to a single value.