13.5.4.24. SHOW TABLE STATUS Syntax
SHOW TABLE STATUS [FROM db_name] [LIKE 'pattern']
SHOW TABLE STATUS works likes SHOW
TABLE, but provides a lot of information about each
table. You can also get this list using the mysqlshow
--status db_name command.
This statement also displays information about views.
SHOW TABLE STATUS returns the following
fields:
-
Name
The name of the table.
-
Engine
The storage engine for the table. See
Chapter 14, Storage Engines and Table Types. Before MySQL 4.1.2,
this value is labeled as Type.
-
Version
The version number of the table's
.frm file.
-
Row_format
The row storage format (Fixed,
Dynamic, Compressed,
Redundant, Compact).
The format of InnoDB tables is reported
as Redundant or
Compact.
-
Rows
The number of rows. Some storage engines, such as
MyISAM, store the exact count.
For other storage engines, such as
InnoDB, this value is an approximation,
and may vary from the actual value by as much as 40 to
50%. In such cases, use SELECT COUNT(*)
to obtain an accurate count.
The Rows value is
NULL for tables in the
INFORMATION_SCHEMA database.
-
Avg_row_length
The average row length.
-
Data_length
The length of the data file.
-
Max_data_length
The maximum length of the data file. This is the total
number of bytes of data that can be stored in the table,
given the data pointer size used.
-
Index_length
The length of the index file.
-
Data_free
The number of allocated but unused bytes.
-
Auto_increment
The next AUTO_INCREMENT value.
-
Create_time
When the table was created.
-
Update_time
When the data file was last updated.
-
Check_time
When the table was last checked. Not all storage engines
update this time, in which case the value is always
NULL.
-
Collation
The table's character set and collation.
-
Checksum
The live checksum value (if any).
-
Create_options
Extra options used with CREATE TABLE.
-
Comment
The comment used when creating the table (or information
as to why MySQL could not access the table information).
In the table comment, InnoDB tables report
the free space of the tablespace to which the table belongs.
For a table located in the shared tablespace, this is the free
space of the shared tablespace. If you are using multiple
tablespaces and the table has its own tablespace, the free
space is for only that table.
For MEMORY tables, the
Data_length,
Max_data_length, and
Index_length values approximate the actual
amount of allocated memory. The allocation algorithm reserves
memory in large amounts to reduce the number of allocation
operations.
For NDB Cluster tables, the output of this
statement shows appropriate values for the
Avg_row_length and
Data_length columns, with the exception
that BLOB columns are not taken into
account. In addition, the number of replicas is shown in the
Comment column (as
number_of_replicas).
For views, all the fields displayed by SHOW TABLE
STATUS are NULL except that
Name indicates the view name and
Comment says view.
