rwlock_instances

This page is part of MariaDB's Enterprise Documentation.

The parent of this page is: Performance Schema

Topics on this page:

Overview
DETAILS
- SCHEMA
CHANGE HISTORY
EXTERNAL REFERENCES

Overview

A description for this Performance-schema Table has not yet been added to this Documentation.

DETAILS

SCHEMA

CREATE TABLE `rwlock_instances` (
  `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock',
  `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock',
  `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.',
  `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held'
)

CHANGE HISTORY

Release Series	History
10.6 Enterprise	Present starting in MariaDB Enterprise Server 10.6.4-1. Schema changed in MariaDB Enterprise Server 10.6.5-2: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.6 Community	Present starting in MariaDB Community Server 10.6.0. Schema changed in MariaDB Community Server 10.6.5: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.5 Enterprise	Present starting in MariaDB Enterprise Server 10.5.3-1. Schema changed in MariaDB Enterprise Server 10.5.13-9: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.5 Community	Present starting in MariaDB Community Server 10.5.0. Schema changed in MariaDB Community Server 10.5.13: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.4 Enterprise	Present starting in MariaDB Enterprise Server 10.4.6-1. Schema changed in MariaDB Community Server 10.4.22-14: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.4 Community	Present starting in MariaDB Community Server 10.4.0. Schema changed in MariaDB Community Server 10.4.22: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.3 Enterprise	Present starting in MariaDB Enterprise Server 10.3.16-1. Schema changed in MariaDB Community Server 10.3.32-14: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.3 Community	Present starting in MariaDB Community Server 10.3.0. Schema changed in MariaDB Community Server 10.3.32: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.2 Enterprise	Present starting in MariaDB Enterprise Server 10.2.25-1. Schema changed in MariaDB Community Server 10.2.41-14: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )
10.2 Community	Present starting in MariaDB Community Server 10.2.0. Schema changed in MariaDB Community Server 10.2.41: ... CREATE TABLE `rwlock_instances` ( `NAME` varchar(128) NOT NULL COMMENT 'Instrument name associated with the read write lock', `OBJECT_INSTANCE_BEGIN` bigint(20) unsigned NOT NULL COMMENT 'Address in memory of the instrumented lock', `WRITE_LOCKED_BY_THREAD_ID` bigint(20) unsigned DEFAULT NULL COMMENT 'THREAD_ID of the locking thread if locked in write (exclusive) mode, otherwise NULL.', `READ_LOCKED_BY_COUNT` int(10) unsigned NOT NULL COMMENT 'Count of current read locks held' )

EXTERNAL REFERENCES

Additional information on this topic may be found in the MariaDB Public Knowledge Base.

Information specific to MariaDB SkySQL can be found on the rwlock_instances page in the SkySQL Documentation.