# Performance Schema threads Table Each server thread is represented as a row in the `threads` table. The `threads` table contains the following columns: | Column | Description | | -------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | | THREAD\_ID | A unique thread identifier. | | NAME | Name associated with the server's thread instrumentation code, for example thread/sql/main for the server's main() function, and thread/sql/one\_connection for a user connection. | | TYPE | FOREGROUND or BACKGROUND, depending on the thread type. User connection threads are FOREGROUND, internal server threads are BACKGROUND. | | PROCESSLIST\_ID | The PROCESSLIST.ID value for threads displayed in the INFORMATION\_SCHEMA.PROCESSLIST table, or 0 for background threads. Also corresponds with the CONNECTION\_ID() return value for the thread. | | PROCESSLIST\_USER | Foreground thread user, or NULL for a background thread. | | PROCESSLIST\_HOST | Foreground thread host, or NULL for a background thread. | | PROCESSLIST\_DB | Thread's default database, or NULL if none exists. | | PROCESSLIST\_COMMAND | Type of command executed by the thread. These correspond to the COM\_xxx client/server protocol commands, and the Com\_xxx [status variables](https://mariadb.com/docs/server/server-management/variables-and-modes/server-status-variables). See [Thread Command Values](https://mariadb.com/docs/server/ha-and-performance/optimization-and-tuning/buffers-caches-and-threads/thread-command-values). | | PROCESSLIST\_TIME | Time in seconds the thread has been in its current state. | | PROCESSLIST\_STATE | Action, event or state indicating what the thread is doing. | | PROCESSLIST\_INFO | Statement being executed by the thread, or NULL if a statement is not being executed. If a statement results in calling other statements, such as for a [stored procedure](https://mariadb.com/docs/server/server-usage/stored-routines/stored-procedures), the innermost statement from the stored procedure is shown here. | | PARENT\_THREAD\_ID | THREAD\_ID of the parent thread, if any. Subthreads can for example be spawned as a result of [INSERT DELAYED](https://mariadb.com/docs/server/reference/sql-statements/data-manipulation/inserting-loading-data/insert-delayed) statements. | | ROLE | Unused. | | INSTRUMENTED | YES or NO for Whether the thread is instrumented or not. For foreground threads, the initial value is determined by whether there's a user/host match in the [setup\_actors](https://mariadb.com/docs/server/reference/system-tables/performance-schema/performance-schema-tables/performance-schema-setup_actors-table) table. Subthreads are again matched, while for background threads, this will be set to YES by default. To monitor events that the thread executes, INSTRUMENTED must be YES and the thread\_instrumentation consumer in the [setup\_consumers](https://mariadb.com/docs/server/reference/system-tables/performance-schema/performance-schema-tables/performance-schema-setup_consumers-table) table must also be YES. | | HISTORY | YES or NO for Whether to log historical events for the thread. For foreground threads, the initial value is determined by whether there's a user/host match in the [setup\_actors](https://mariadb.com/docs/server/reference/system-tables/performance-schema/performance-schema-tables/performance-schema-setup_actors-table) table. Subthreads are again matched, while for background threads, this will be set to YES by default. To monitor events that the thread executes, INSTRUMENTED must be YES and the thread\_instrumentation consumer in the [setup\_consumers](https://mariadb.com/docs/server/reference/system-tables/performance-schema/performance-schema-tables/performance-schema-setup_consumers-table) table must also be YES. Added in [MariaDB 10.5](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/10.5/what-is-mariadb-105). | | CONNECTION\_TYPE | The protocol used to establish the connection. One of TCP/IP, SSL/TLS, Socket, Named Pipe, Shared Memory, or NULL for background threads. Added in [MariaDB 10.5](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/10.5/what-is-mariadb-105). | | THREAD\_OS\_ID | The thread or task identifier as defined by the underlying operating system, if there is one. Added in [MariaDB 10.5](https://app.gitbook.com/s/aEnK0ZXmUbJzqQrTjFyb/community-server/old-releases/10.5/what-is-mariadb-105) | ## Example ```sql SELECT * FROM performance_schema.threads\G; *************************** 1. row *************************** THREAD_ID: 1 NAME: thread/sql/main TYPE: BACKGROUND PROCESSLIST_ID: NULL PROCESSLIST_USER: NULL PROCESSLIST_HOST: NULL PROCESSLIST_DB: NULL PROCESSLIST_COMMAND: NULL PROCESSLIST_TIME: 215859 PROCESSLIST_STATE: Table lock PROCESSLIST_INFO: INTERNAL DDL LOG RECOVER IN PROGRESS PARENT_THREAD_ID: NULL ROLE: NULL INSTRUMENTED: YES ... *************************** 21. row *************************** THREAD_ID: 64 NAME: thread/sql/one_connection TYPE: FOREGROUND PROCESSLIST_ID: 44 PROCESSLIST_USER: root PROCESSLIST_HOST: localhost PROCESSLIST_DB: NULL PROCESSLIST_COMMAND: Query PROCESSLIST_TIME: 0 PROCESSLIST_STATE: Sending data PROCESSLIST_INFO: SELECT * FROM performance_schema.threads PARENT_THREAD_ID: NULL ROLE: NULL INSTRUMENTED: YES ``` *This page is licensed: CC BY-SA / Gnu FDL* {% @marketo/form formId="4316" %}