Oracle 5.0 Reference Manual page 1311

Performance Tuning and Troubleshooting
InnoDB
This section provides information about the most recent foreign key constraint error. It is not present if
no such error has occurred. The contents include the statement that failed as well as information about
the constraint that failed and the referenced and referencing tables.
LATEST DETECTED DEADLOCK
This section provides information about the most recent deadlock. It is not present if no deadlock has
occurred. The contents show which transactions are involved, the statement each was attempting to
execute, the locks they have and need, and which transaction decided to roll back to break
InnoDB
the deadlock. The lock modes reported in this section are explained in Section 14.2.7.1, "InnoDB Lock
Modes".
TRANSACTIONS
If this section reports lock waits, your applications might have lock contention. The output can also help
to trace the reasons for transaction deadlocks.
FILE I/O
This section provides information about threads that uses to perform various types of I/O. The
InnoDB
first few of these are dedicated to general processing. The contents also display information
InnoDB
for pending I/O operations and statistics for I/O performance.
On Unix, the number of threads is always 4. On Windows, the number depends on the setting of the
[1241] system variable.
innodb_file_io_threads
INSERT BUFFER AND ADAPTIVE HASH INDEX
This section shows the status of the insert buffer and adaptive hash index. (See
InnoDB
Section 14.2.9.3, "Insert Buffering", and Section 14.2.9.4, "Adaptive Hash Indexes".) The contents
include the number of operations performed for each, plus statistics for hash index performance.
LOG
This section displays information about the log. The contents include the current log sequence
InnoDB
number, how far the log has been flushed to disk, and the position at which last took a
InnoDB
checkpoint. (See Section 14.2.5.3, "InnoDB Checkpoints".) The section also displays information about
pending writes and write performance statistics.
BUFFER POOL AND MEMORY
This section gives you statistics on pages read and written. You can calculate from these numbers how
many data file I/O operations your queries currently are doing.
For additional information about the operation of the buffer pool, see Section 8.6.2, "The Buffer
InnoDB
Pool".
ROW OPERATIONS
This section shows what the main thread is doing, including the number and performance rate for each
type of row operation.
14.2.12.2.2. Tablespace Monitor Output
InnoDB
The Tablespace Monitor prints information about the file segments in the shared tablespace
InnoDB
and validates the tablespace allocation data structures. If you use individual tablespaces by enabling
[1241], the Tablespace Monitor does not describe those tablespaces.
innodb_file_per_table
Example Tablespace Monitor output:
InnoDB
================================================
090408 21:28:09 INNODB TABLESPACE MONITOR OUTPUT
================================================
1291