SHOW ENGINE engine_name
{LOGS | STATUS }
SHOW ENGINE
displays log or
status information about a storage engine. The following
statements currently are supported:
SHOW ENGINE BDB LOGS SHOW ENGINE INNODB STATUS SHOW ENGINE NDB STATUS SHOW ENGINE NDBCLUSTER STATUS
SHOW ENGINE BDB
LOGS
displays status information about existing
BDB
log files. It returns the following
fields:
File
The full path to the log file.
Type
The log file type (BDB
for Berkeley DB
log files).
Status
The status of the log file (FREE
if the
file can be removed, or IN USE
if the
file is needed by the transaction subsystem)
SHOW ENGINE INNODB
STATUS
displays extensive information from the
standard InnoDB
Monitor about the state of
the InnoDB
storage engine. For information
about the standard monitor and other InnoDB
Monitors that provide information about
InnoDB
processing, see
Section 13.2.14.2, “SHOW ENGINE INNODB
STATUS
and the InnoDB
Monitors”.
Older (and now deprecated) synonyms for these statements are
SHOW [BDB] LOGS
and SHOW
INNODB STATUS
.
SHOW ENGINE
can be used as of
MySQL 4.1.2.
Beginning with MySQL 4.1.3, if the server has the
NDBCLUSTER
storage engine enabled,
SHOW ENGINE NDB
STATUS
can be used to display cluster status
information. Sample output from this statement is shown here:
mysql> SHOW ENGINE NDB STATUS;
+-----------------------+---------+------+--------+
| free_list | created | free | sizeof |
+-----------------------+---------+------+--------+
| NdbTransaction | 5 | 0 | 208 |
| NdbOperation | 4 | 4 | 660 |
| NdbIndexScanOperation | 1 | 1 | 736 |
| NdbIndexOperation | 0 | 0 | 1060 |
| NdbRecAttr | 645 | 645 | 72 |
| NdbApiSignal | 16 | 16 | 136 |
| NdbLabel | 0 | 0 | 196 |
| NdbBranch | 0 | 0 | 24 |
| NdbSubroutine | 0 | 0 | 68 |
| NdbCall | 0 | 0 | 16 |
| NdbBlob | 2 | 2 | 204 |
| NdbReceiver | 2 | 0 | 68 |
+-----------------------+---------+------+--------+
12 rows in set (0.00 sec)
The most useful of the rows from the output of this statement are described in the following list:
NdbTransaction
: The number and size of
NdbTransaction
objects that have been
created. An NdbTransaction
is created
each time a table schema operation (such as
CREATE TABLE
or
ALTER TABLE
) is performed on
an NDB
table.
NdbOperation
: The number and size of
NdbOperation
objects that have been
created.
NdbIndexScanOperation
: The number and
size of NdbIndexScanOperation
objects
that have been created.
NdbIndexOperation
: The number and size of
NdbIndexOperation
objects that have been
created.
NdbRecAttr
: The number and size of
NdbRecAttr
objects that have been
created. In general, one of these is created each time a
data manipulation statement is performed by an SQL node.
NdbBlob
: The number and size of
NdbBlob
objects that have been created.
An NdbBlob
is created for each new
operation involving a BLOB
column in an NDB
table.
NdbReceiver
: The number and size of any
NdbReceiver
object that have been
created. The number in the created
column
is the same as the number of data nodes in the cluster to
which the MySQL server has connected.
SHOW ENGINE NDB
STATUS
returns an empty result if no operations
involving NDB
tables have been
performed by the MySQL client accessing the SQL node on which
this statement is run.
SHOW ENGINE
NDBCLUSTER STATUS
is a synonym for
SHOW ENGINE NDB
STATUS
.
MySQL Enterprise.
The SHOW ENGINE
statement provides valuable information about the state of
your server. For expert interpretation of this information,
subscribe to the MySQL Enterprise Monitor. For more
information, see http://www.mysql.com/products/enterprise/advisors.html.
engine_name
STATUS
User Comments
Add your own comment.