Note
This view is available starting with V2.2.30.
Purpose
The DBA_TAB_COLUMNS view contains a row for each column in each table and view in the database.
Applicability
This view applies only to OceanBase Database in Oracle mode.
Columns
| Column | Type | Nullable? | Description |
|---|---|---|---|
| OWNER | VARCHAR2(128) | NO | The owner of the table or view. |
| TABLE_NAME | VARCHAR2(128) | NO | The name of the table or view. |
| COLUMN_NAME | VARCHAR2(128) | NO | The name of the column. |
| DATA_TYPE | VARCHAR2(128) | NO | The data type of the column. |
| DATA_TYPE_MOD | VARCHAR2(3) | NO | Not supported. The default value is NULL. |
| DATA_TYPE_OWNER | VARCHAR2(128) | NO | Not supported. The default value is NULL. |
| DATA_LENGTH | NUMBER | NO | The length of the column in bytes. |
| DATA_PRECISION | NUMBER | NO | The decimal precision of the column if it is a numeric data type; the binary precision of the column if it is a floating-point data type; otherwise, NULL. |
| DATA_SCALE | NUMBER | NO | The number of digits to the right of the decimal point in the column. |
| NULLABLE | VARCHAR2(1) | NO | Indicates whether the column allows NULL values. |
| COLUMN_ID | NUMBER | NO | The column ID. |
| DEFAULT_LENGTH | NUMBER | NO | The default length of the column. |
| DATA_DEFAULT | VARCHAR2(128) | NO | The default value of the column. |
| NUM_DISTINCT | NUMBER | NO | The number of distinct values in the column. |
| LOW_VALUE | VARCHAR2(128) | NO | The minimum value in the column. |
| HIGH_VALUE | VARCHAR2(128) | NO | The maximum value in the column. |
| DENSITY | NUMBER | NO | The density of the column. |
| NUM_NULLS | NUMBER | NO | The number of NULL values in the column. |
| NUM_BUCKETS | NUMBER | NO | The number of buckets in the histogram of the column. |
| LAST_ANALYZED | DATE | NO | The time when the column was last analyzed. |
| SAMPLE_SIZE | NUMBER | NO | The sample size when the column was analyzed. |
| CHARACTER_SET_NAME | VARCHAR2(44) | NO | The character set name: CHAR_CSNCHAR_CS |
| CHAR_COL_DECL_LENGTH | NUMBER | NO | Not supported. The default value is NULL. |
| GLOBAL_STATS | VARCHAR2(3) | NO | YES if the statistics are collected or incrementally maintained, otherwise NO. |
| USER_STATS | VARCHAR2(3) | NO | YES if the statistics are directly entered by the user, otherwise NO. |
| AVG_COL_LEN | NUMBER | NO | The average length of the column in bytes. |
| CHAR_LENGTH | NUMBER | NO | The length of the column if it is a character data type. |
| CHAR_USED | VARCHAR2(1) | NO | Indicates whether the column length is measured in bytes or characters. |
| V80_FMT_IMAGE | VARCHAR2(3) | NO | Not supported. The default value is NULL. |
| DATA_UPGRADED | VARCHAR2(3) | NO | Not supported. The default value is NULL. |
| HISTOGRAM | VARCHAR2(15) | NO | The histogram type. |
| DEFAULT_ON_NULL | VARCHAR2(3) | NO | Not supported. The default value is NULL. |
| IDENTITY_COLUMN | VARCHAR2(3) | NO | Not supported. The default value is NULL |
| EVALUATION_EDITION | VARCHAR2(128) | NO | Not supported. The default value is NULL |
| UNUSABLE_BEFORE | VARCHAR2(128) | NO | Not supported. The default value is NULL |
| UNUSABLE_BEGINNING | VARCHAR2(128) | NO | Not supported. The default value is NULL |
| COLLATION | VARCHAR2(100) | NO | Not supported. The default value is NULL |
Sample query
Query all columns of the T_SUBPART table in the current tenant.
obclient [SYS]> SELECT * FROM SYS.DBA_TAB_COLUMNS WHERE TABLE_NAME ='T_SUBPART'\G
The query result is as follows:
*************************** 1. row ***************************
OWNER: SYS
TABLE_NAME: T_SUBPART
COLUMN_NAME: NO
DATA_TYPE: NUMBER
DATA_TYPE_MOD: NULL
DATA_TYPE_OWNER: NULL
DATA_LENGTH: 22
DATA_PRECISION: NULL
DATA_SCALE: NULL
NULLABLE: Y
COLUMN_ID: 16
DEFAULT_LENGTH: NULL
DATA_DEFAULT: NULL
NUM_DISTINCT: 1034
LOW_VALUE: 2
HIGH_VALUE: 1001
DENSITY: 0
NUM_NULLS: 0
NUM_BUCKETS: 0
LAST_ANALYZED: 25-MAR-25
SAMPLE_SIZE: 1000
CHARACTER_SET_NAME: NULL
CHAR_COL_DECL_LENGTH: NULL
GLOBAL_STATS: NO
USER_STATS: NO
AVG_COL_LEN: 20
CHAR_LENGTH: 0
CHAR_USED: NULL
V80_FMT_IMAGE: NULL
DATA_UPGRADED: NULL
HISTOGRAM: NULL
DEFAULT_ON_NULL: NULL
IDENTITY_COLUMN: NULL
EVALUATION_EDITION: NULL
UNUSABLE_BEFORE: NULL
UNUSABLE_BEGINNING: NULL
COLLATION: NULL
*************************** 2. row ***************************
OWNER: SYS
TABLE_NAME: T_SUBPART
COLUMN_NAME: ID
DATA_TYPE: NUMBER
DATA_TYPE_MOD: NULL
DATA_TYPE_OWNER: NULL
DATA_LENGTH: 22
DATA_PRECISION: NULL
DATA_SCALE: NULL
NULLABLE: Y
COLUMN_ID: 17
DEFAULT_LENGTH: NULL
DATA_DEFAULT: NULL
NUM_DISTINCT: 10
LOW_VALUE: 1
HIGH_VALUE: 999
DENSITY: 0
NUM_NULLS: 0
NUM_BUCKETS: 0
LAST_ANALYZED: 25-MAR-25
SAMPLE_SIZE: 1000
CHARACTER_SET_NAME: NULL
CHAR_COL_DECL_LENGTH: NULL
GLOBAL_STATS: NO
USER_STATS: NO
AVG_COL_LEN: 20
CHAR_LENGTH: 0
CHAR_USED: NULL
V80_FMT_IMAGE: NULL
DATA_UPGRADED: NULL
HISTOGRAM: NULL
DEFAULT_ON_NULL: NULL
IDENTITY_COLUMN: NULL
EVALUATION_EDITION: NULL
UNUSABLE_BEFORE: NULL
UNUSABLE_BEGINNING: NULL
COLLATION: NULL
*************************** 3. row ***************************
OWNER: SYS
TABLE_NAME: T_SUBPART
COLUMN_NAME: TEST_DATE
DATA_TYPE: DATE
DATA_TYPE_MOD: NULL
DATA_TYPE_OWNER: NULL
DATA_LENGTH: 7
DATA_PRECISION: NULL
DATA_SCALE: NULL
NULLABLE: Y
COLUMN_ID: 18
DEFAULT_LENGTH: NULL
DATA_DEFAULT: NULL
NUM_DISTINCT: 3
LOW_VALUE: '2022-12-15 00:00:00'
HIGH_VALUE: '2024-01-10 00:00:00'
DENSITY: 0
NUM_NULLS: 0
NUM_BUCKETS: 0
LAST_ANALYZED: 25-MAR-25
SAMPLE_SIZE: 1000
CHARACTER_SET_NAME: NULL
CHAR_COL_DECL_LENGTH: NULL
GLOBAL_STATS: NO
USER_STATS: NO
AVG_COL_LEN: 20
CHAR_LENGTH: 0
CHAR_USED: NULL
V80_FMT_IMAGE: NULL
DATA_UPGRADED: NULL
HISTOGRAM: NULL
DEFAULT_ON_NULL: NULL
IDENTITY_COLUMN: NULL
EVALUATION_EDITION: NULL
UNUSABLE_BEFORE: NULL
UNUSABLE_BEGINNING: NULL
COLLATION: NULL
*************************** 4. row ***************************
OWNER: SYS
TABLE_NAME: T_SUBPART
COLUMN_NAME: QUANTITY
DATA_TYPE: NUMBER
DATA_TYPE_MOD: NULL
DATA_TYPE_OWNER: NULL
DATA_LENGTH: 22
DATA_PRECISION: NULL
DATA_SCALE: NULL
NULLABLE: Y
COLUMN_ID: 19
DEFAULT_LENGTH: NULL
DATA_DEFAULT: NULL
NUM_DISTINCT: 2
LOW_VALUE: 1
HIGH_VALUE: 1000
DENSITY: 0
NUM_NULLS: 0
NUM_BUCKETS: 0
LAST_ANALYZED: 25-MAR-25
SAMPLE_SIZE: 1000
CHARACTER_SET_NAME: NULL
CHAR_COL_DECL_LENGTH: NULL
GLOBAL_STATS: NO
USER_STATS: NO
AVG_COL_LEN: 20
CHAR_LENGTH: 0
CHAR_USED: NULL
V80_FMT_IMAGE: NULL
DATA_UPGRADED: NULL
HISTOGRAM: NULL
DEFAULT_ON_NULL: NULL
IDENTITY_COLUMN: NULL
EVALUATION_EDITION: NULL
UNUSABLE_BEFORE: NULL
UNUSABLE_BEGINNING: NULL
COLLATION: NULL
4 rows in set
References
ALL_TAB_COLUMNS: view all columns of all tables and views accessible to the current user.
USER_TAB_COLUMNS: view all columns of tables and views owned by the current user.