3.2 Locking

InnoDB Row Lock Waits

Displays the InnoDB locks transactions are waiting for. Values are taken from the sys.x$innodb_lock_waits view.

Table 3.2 InnoDB Row Lock Waits Dashboard

Name	Description
Waiting Lock ID	The ID of the waiting lock.
Waiting Trx ID	The ID of the waiting transaction.
Blocking Lock ID	The ID of the lock that is blocking the waiting lock.
Blocking Lock Mode	The mode of the lock that is blocking the waiting lock.
Blocking PID	The processlist ID of the blocking transaction.
Blocking Query	The statement the blocking transaction is executing.
Blocking Trx Age	How long the blocking transaction has been executing, as a TIME value.
Blocking Trx ID	The ID of the transaction that is blocking the waiting lock.
Blocking Trx Rows Locked	The number of rows locked by the blocking transaction.
Blocking Trx Rows Modified	The number of rows modified by the blocking transaction.
Blocking Trx Started	The time at which the blocking transaction started.
Locked Index	The name of the locked index.
Locked Table	The name of the locked table.
Locked Type	The type of the waiting lock.
Wait Age	How long the lock has been waited for, as a TIME value.
Waiting Lock Mode	The mode of the waiting lock.
Waiting PID	The processlist ID of the waiting transaction.
Waiting Query	The statement that is waiting for the lock.
Waiting Trx Age	How long the waiting transaction has been waiting, as a TIME value.
Waiting Trx Rows Locked	The number of rows locked by the waiting transaction.
Waiting Trx Rows Modified	The number of rows modified by the waiting transaction.
Waiting Trx Started	The time at which the waiting transaction started.
Wait Started	The time at which the lock wait started.

Table Metadata Lock Waits

This dashboard displays which sessions are blocked waiting on metadata locks, and what is blocking them. Values are retrieved from the sys.x$schema_table_lock_waits view.

Table 3.3 Table Metadata Lock Waits Dashboard

Name	Description
Object Name	The name of the instrumented object.
Object Schema	The schema containing the locked object.
Blocking Account	The account associated with the thread that is blocking the waiting lock.
Blocking Account Duration	How long the blocking lock has been held.
Blocking Lock Type	The type of lock that is blocking the waiting lock.
Blocking PID	The processlist ID of the thread that is blocking the waiting lock.
Blocking Thread ID	The thread ID of the thread that is blocking the waiting lock.
Waiting Account	The account associated with the session that is waiting for the lock.
Waiting Lock Duration	How long the waiting lock has been waiting.
Waiting Lock Type	The type of the waiting lock.
Waiting PID	The processlist ID of the thread that is waiting for the lock.
Waiting Query	The statement that is waiting for the lock.
Waiting Query Rows Affected	The number of rows affected by the statement.
Waiting Query Rows Examined	The number of rows read from storage engines by the statement.
Waiting Query Secs	How long the statement has been waiting, in seconds.
Waiting Thread ID	The thread ID of the thread that is waiting for the lock.