28.4.23 INFORMATION_SCHEMA INNODB_TABLES 表
The INNODB_TABLES
table provides metadata about InnoDB
tables.
For related usage information and examples, see Section 17.15.3, “InnoDB INFORMATION_SCHEMA Schema Object Tables”.
The INNODB_TABLES
table has these columns:
-
TABLE_ID
An identifier for the
InnoDB
table. This value is unique across all databases in the instance. -
NAME
The name of the table, preceded by the schema (database) name where appropriate (for example,
test/t1
). Names of databases and user tables are in the same case as they were originally defined, possibly influenced by thelower_case_table_names
setting. -
FLAG
A numeric value that represents bit-level information about table format and storage characteristics.
-
N_COLS
The number of columns in the table. The number reported includes three hidden columns that are created by
InnoDB
(DB_ROW_ID
,DB_TRX_ID
, andDB_ROLL_PTR
). The number reported also includes virtual generated columns, if present. -
SPACE
An identifier for the tablespace where the table resides. 0 means the
InnoDB
system tablespace. Any other number represents either a file-per-table tablespace or a general tablespace. This identifier stays the same after aTRUNCATE TABLE
statement. For file-per-table tablespaces, this identifier is unique for tables across all databases in the instance. -
ROW_FORMAT
The table's row format (
Compact
,Redundant
,Dynamic
, orCompressed
). -
ZIP_PAGE_SIZE
The zip page size. Applies only to tables with a row format of
Compressed
. -
SPACE_TYPE
The type of tablespace to which the table belongs. Possible values include
System
for the system tablespace,General
for general tablespaces, andSingle
for file-per-table tablespaces. Tables assigned to the system tablespace usingCREATE TABLE
orALTER TABLE
TABLESPACE=innodb_system
have aSPACE_TYPE
ofGeneral
. For more information, seeCREATE TABLESPACE
. -
INSTANT_COLS
The number of columns that existed before the first instant column was added using
ALTER TABLE ... ADD COLUMN
withALGORITHM=INSTANT
. This column is no longer used. -
TOTAL_ROW_VERSIONS
The number of row versions for the table. The initial value is 0. The value is incremented by
ALTER TABLE ... ALGORITHM=INSTANT
operations that add or remove columns. When a table with instantly added or dropped columns is rebuilt due to a table-rebuildingALTER TABLE
orOPTIMIZE TABLE
operation, the value is reset to 0. For more information, see Column Operations.
mysql> SELECT * FROM INFORMATION_SCHEMA.INNODB_TABLES WHERE TABLE_ID = 214\G
*************************** 1. row ***************************
TABLE_ID: 1064
NAME: test/t1
FLAG: 33
N_COLS: 6
SPACE: 3
ROW_FORMAT: Dynamic
ZIP_PAGE_SIZE: 0
SPACE_TYPE: Single
INSTANT_COLS: 0
TOTAL_ROW_VERSIONS: 3
-
You must have the
PROCESS
privilege to query this table. -
Use the
INFORMATION_SCHEMA
COLUMNS
table or theSHOW COLUMNS
statement to view additional information about the columns of this table, including data types and default values.