Performance Schema table_lock_waits_summary_by_table Table

MariaDB starting with 10.0

The table_lock_waits_summary_by_table table, along with many other new Performance Schema tables, was added in MariaDB 10.0.

The table_lock_waits_summary_by_table table records table lock waits by table.

ColumnDescription
OBJECT_TYPESince this table records waits by table, always set to TABLE.
OBJECT_SCHEMASchema name.
OBJECT_NAMETable name.
COUNT_STARNumber of summarized events and the sum of the x_READ and x_WRITE columns.
SUM_TIMER_WAITTotal wait time of the summarized events that are timed.
MIN_TIMER_WAITMinimum wait time of the summarized events that are timed.
AVG_TIMER_WAITAverage wait time of the summarized events that are timed.
MAX_TIMER_WAITMaximum wait time of the summarized events that are timed.
COUNT_READNumber of all read operations, and the sum of the equivalent x_READ_NORMAL, x_READ_WITH_SHARED_LOCKS, x_READ_HIGH_PRIORITY and x_READ_NO_INSERT columns.
SUM_TIMER_READTotal wait time of all read operations that are timed.
MIN_TIMER_READMinimum wait time of all read operations that are timed.
AVG_TIMER_READAverage wait time of all read operations that are timed.
MAX_TIMER_READMaximum wait time of all read operations that are timed.
COUNT_WRITENumber of all write operations, and the sum of the equivalent x_WRITE_ALLOW_WRITE, x_WRITE_CONCURRENT_INSERT, x_WRITE_DELAYED, x_WRITE_LOW_PRIORITY and x_WRITE_NORMAL columns.
SUM_TIMER_WRITETotal wait time of all write operations that are timed.
MIN_TIMER_WRITEMinimum wait time of all write operations that are timed.
AVG_TIMER_WRITEAverage wait time of all write operations that are timed.
MAX_TIMER_WRITEMaximum wait time of all write operations that are timed.
COUNT_READ_NORMALNumber of all internal read normal locks.
SUM_TIMER_READ_NORMALTotal wait time of all internal read normal locks that are timed.
MIN_TIMER_READ_NORMALMinimum wait time of all internal read normal locks that are timed.
AVG_TIMER_READ_NORMALAverage wait time of all internal read normal locks that are timed.
MAX_TIMER_READ_NORMALMaximum wait time of all internal read normal locks that are timed.
COUNT_READ_WITH_SHARED_LOCKSNumber of all internal read with shared locks.
SUM_TIMER_READ_WITH_SHARED_LOCKSTotal wait time of all internal read with shared locks that are timed.
MIN_TIMER_READ_WITH_SHARED_LOCKSMinimum wait time of all internal read with shared locks that are timed.
AVG_TIMER_READ_WITH_SHARED_LOCKSAverage wait time of all internal read with shared locks that are timed.
MAX_TIMER_READ_WITH_SHARED_LOCKSMaximum wait time of all internal read with shared locks that are timed.
COUNT_READ_HIGH_PRIORITYNumber of all internal read high priority locks.
SUM_TIMER_READ_HIGH_PRIORITYTotal wait time of all internal read high priority locks that are timed.
MIN_TIMER_READ_HIGH_PRIORITYMinimum wait time of all internal read high priority locks that are timed.
AVG_TIMER_READ_HIGH_PRIORITYAverage wait time of all internal read high priority locks that are timed.
MAX_TIMER_READ_HIGH_PRIORITYMaximum wait time of all internal read high priority locks that are timed.
COUNT_READ_NO_INSERTNumber of all internal read no insert locks.
SUM_TIMER_READ_NO_INSERTTotal wait time of all internal read no insert locks that are timed.
MIN_TIMER_READ_NO_INSERTMinimum wait time of all internal read no insert locks that are timed.
AVG_TIMER_READ_NO_INSERTAverage wait time of all internal read no insert locks that are timed.
MAX_TIMER_READ_NO_INSERTMaximum wait time of all internal read no insert locks that are timed.
COUNT_READ_EXTERNALNumber of all external read locks.
SUM_TIMER_READ_EXTERNALTotal wait time of all external read locks that are timed.
MIN_TIMER_READ_EXTERNALMinimum wait time of all external read locks that are timed.
AVG_TIMER_READ_EXTERNALAverage wait time of all external read locks that are timed.
MAX_TIMER_READ_EXTERNALMaximum wait time of all external read locks that are timed.
COUNT_WRITE_ALLOW_WRITENumber of all internal read normal locks.
SUM_TIMER_WRITE_ALLOW_WRITETotal wait time of all internal write allow write locks that are timed.
MIN_TIMER_WRITE_ALLOW_WRITEMinimum wait time of all internal write allow write locks that are timed.
AVG_TIMER_WRITE_ALLOW_WRITEAverage wait time of all internal write allow write locks that are timed.
MAX_TIMER_WRITE_ALLOW_WRITEMaximum wait time of all internal write allow write locks that are timed.
COUNT_WRITE_CONCURRENT_INSERTNumber of all internal concurrent insert write locks.
SUM_TIMER_WRITE_CONCURRENT_INSERTTotal wait time of all internal concurrent insert write locks that are timed.
MIN_TIMER_WRITE_CONCURRENT_INSERTMinimum wait time of all internal concurrent insert write locks that are timed.
AVG_TIMER_WRITE_CONCURRENT_INSERTAverage wait time of all internal concurrent insert write locks that are timed.
MAX_TIMER_WRITE_CONCURRENT_INSERTMaximum wait time of all internal concurrent insert write locks that are timed.
COUNT_WRITE_DELAYEDNumber of all internal write delayed locks.
SUM_TIMER_WRITE_DELAYEDTotal wait time of all internal write delayed locks that are timed.
MIN_TIMER_WRITE_DELAYEDMinimum wait time of all internal write delayed locks that are timed.
AVG_TIMER_WRITE_DELAYEDAverage wait time of all internal write delayed locks that are timed.
MAX_TIMER_WRITE_DELAYEDMaximum wait time of all internal write delayed locks that are timed.
COUNT_WRITE_LOW_PRIORITYNumber of all internal write low priority locks.
SUM_TIMER_WRITE_LOW_PRIORITYTotal wait time of all internal write low priority locks that are timed.
MIN_TIMER_WRITE_LOW_PRIORITYMinimum wait time of all internal write low priority locks that are timed.
AVG_TIMER_WRITE_LOW_PRIORITYAverage wait time of all internal write low priority locks that are timed.
MAX_TIMER_WRITE_LOW_PRIORITYMaximum wait time of all internal write low priority locks that are timed.
COUNT_WRITE_NORMALNumber of all internal write normal locks.
SUM_TIMER_WRITE_NORMALTotal wait time of all internal write normal locks that are timed.
MIN_TIMER_WRITE_NORMALMinimum wait time of all internal write normal locks that are timed.
AVG_TIMER_WRITE_NORMALAverage wait time of all internal write normal locks that are timed.
MAX_TIMER_WRITE_NORMALMaximum wait time of all internal write normal locks that are timed.
COUNT_WRITE_EXTERNALNumber of all external write locks.
SUM_TIMER_WRITE_EXTERNALTotal wait time of all external write locks that are timed.
MIN_TIMER_WRITE_EXTERNALMinimum wait time of all external write locks that are timed.
AVG_TIMER_WRITE_EXTERNALAverage wait time of all external write locks that are timed.
MAX_TIMER_WRITE_EXTERNALMaximum wait time of all external write locks that are timed.

You can TRUNCATE the table, which will reset all counters to zero.

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