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.