MySQL 8.0 Reference Manual
Related Documentation Download this Manual
PDF (US Ltr)- 41.6Mb
PDF (A4)- 41.7Mb
Man Pages (TGZ)- 262.2Kb
Man Pages (Zip)- 372.3Kb
Info (Gzip)- 4.0Mb
Info (Zip)- 4.0Mb
Excerpts from this Manual


The MySQL process list indicates the operations currently being performed by the set of threads executing within the server. ThePROCESSLISTtable is one source of process information. For a comparison of this table with other sources, seeSources of Process Information

ThePROCESSLISTtable has these columns:

  • ID

    The connection identifier. This is the same value displayed in theIdcolumn of theSHOW PROCESSLISTstatement, displayed in thePROCESSLIST_IDcolumn of the Performance Schemathreadstable, and returned by theCONNECTION_ID()function within the thread.

  • USER

    The MySQL user who issued the statement. A value ofsystem userrefers to a nonclient thread spawned by the server to handle tasks internally, for example, a delayed-row handler thread or an I/O or SQL thread used on replica hosts. Forsystem user, there is no host specified in theHostcolumn.unauthenticated userrefers to a thread that has become associated with a client connection but for which authentication of the client user has not yet occurred.event_schedulerrefers to the thread that monitors scheduled events (seeSection 25.4, “Using the Event Scheduler”).


    AUSERvalue ofsystem useris distinct from theSYSTEM_USERprivilege. The former designates internal threads. The latter distinguishes the system user and regular user account categories (seeSection 6.2.11, “Account Categories”).

  • HOST

    The host name of the client issuing the statement (except forsystem user, for which there is no host). The host name for TCP/IP connections is reported inhost_name:client_portformat to make it easier to determine which client is doing what.

  • DB

    The default database for the thread, orNULLif none has been selected.


    The type of command the thread is executing on behalf of the client, orSleepif the session is idle. For descriptions of thread commands, seeSection 8.14, “Examining Server Thread (Process) Information”。这一列对应的值COM_xxx和命令的客户机/服务器协议Com_xxxstatus variables. SeeSection 5.1.10, “Server Status Variables”

  • TIME

    The time in seconds that the thread has been in its current state. For a replica SQL thread, the value is the number of seconds between the timestamp of the last replicated event and the real time of the replica host. SeeSection 17.2.3, “Replication Threads”


    An action, event, or state that indicates what the thread is doing. For descriptions ofSTATEvalues, seeSection 8.14, “Examining Server Thread (Process) Information”

    Most states correspond to very quick operations. If a thread stays in a given state for many seconds, there might be a problem that needs to be investigated.

  • 信息

    The statement the thread is executing, orNULLif it is executing no statement. The statement might be the one sent to the server, or an innermost statement if the statement executes other statements. For example, if aCALLstatement executes a stored procedure that is executing aSELECTstatement, the信息value shows theSELECTstatement.


  • PROCESSLISTis a nonstandard信息RMATION_SCHEMAtable.

  • Like the output from theSHOW PROCESSLISTstatement, thePROCESSLISTtable provides information about all threads, even those belonging to other users, if you have thePROCESSprivilege. Otherwise (without thePROCESSprivilege), nonanonymous users have access to information about their own threads but not threads for other users, and anonymous users have no access to thread information.

  • If an SQL statement refers to thePROCESSLISTtable, MySQL populates the entire table once, when statement execution begins, so there is read consistency during the statement. There is no read consistency for a multi-statement transaction.

The following statements are equivalent: