ALL_TAB_COLUMNS
describes the columns of the tables, views, and clusters accessible to the current user. To gather statistics for this view, use the ANALYZE
SQL statement or the DBMS_STATS
package.
DBA_TAB_COLUMNS
describes the columns of all tables, views, and clusters in the database.
USER_TAB_COLUMNS
describes the columns of the tables, views, and clusters owned by the current user. This view does not display the OWNER
column.
Column | Datatype | NULL | Description |
---|---|---|---|
OWNER |
VARCHAR2(30) |
NOT NULL |
Owner of the table, view, or cluster |
TABLE_NAME |
VARCHAR2(30) |
NOT NULL |
Name of the table, view, or cluster |
COLUMN_NAME |
VARCHAR2(30) |
NOT NULL |
Column name |
DATA_TYPE |
VARCHAR2(106) |
Datatype of the column | |
DATA_TYPE_MOD |
VARCHAR2(3) |
Datatype modifier of the column | |
DATA_TYPE_OWNER |
VARCHAR2(30) |
Owner of the datatype of the column | |
DATA_LENGTH |
NUMBER |
NOT NULL |
Length of the column (in bytes) |
DATA_PRECISION |
NUMBER |
Decimal precision for NUMBER datatype; binary precision for FLOAT datatype, null for all other datatypes |
|
DATA_SCALE |
NUMBER |
Digits to right of decimal point in a number | |
NULLABLE |
VARCHAR2(1) |
Specifies whether a column allows NULLs. Value is N if there is a NOT NULL constraint on the column or if the column is part of a PRIMARY KEY. The constraint should be in an ENABLE VALIDATE state. |
|
COLUMN_ID |
NUMBER |
Sequence number of the column as created | |
DEFAULT_LENGTH |
NUMBER |
Length of default value for the column | |
DATA_DEFAULT |
LONG |
Default value for the column | |
NUM_DISTINCT |
NUMBER |
Number of distinct values in the columnFoot 1 | |
LOW_VALUE |
RAW(32) |
Low value in the columnFootref 1 | |
HIGH_VALUE |
RAW(32) |
High value in the columnFootref 1 | |
DENSITY |
NUMBER |
Density of the columnFootref 1 | |
NUM_NULLS |
NUMBER |
Number of nulls in the column | |
NUM_BUCKETS |
NUMBER |
Number of buckets in the histogram for the column
Note: The number of buckets in a histogram is specified in the |
|
LAST_ANALYZED |
DATE |
Date on which this column was most recently analyzed | |
SAMPLE_SIZE |
NUMBER |
Sample size used in analyzing this column | |
CHARACTER_SET_NAME |
VARCHAR2(44) |
Name of the character set: CHAR_CS or NCHAR_CS |
|
CHAR_COL_DECL_LENGTH |
NUMBER |
Length | |
GLOBAL_STATS |
VARCHAR2(3) |
For partitioned tables, indicates whether column statistics were collected for the table as a whole (YES ) or were estimated from statistics on underlying partitions and subpartitions (NO ) |
|
USER_STATS |
VARCHAR2(3) |
Indicates whether statistics were entered directly by the user (YES ) or not (NO ) |
|
AVG_COL_LEN |
NUMBER |
Average length of the column (in bytes) | |
CHAR_LENGTH |
NUMBER |
Displays the length of the column in characters. This value only applies to the following datatypes:
|
|
CHAR_USED |
VARCHAR2(1) |
B | C . B indicates that the column uses BYTE length semantics. C indicates that the column uses CHAR length semantics. NULL indicates the datatype is not any of the following:
|
|
V80_FMT_IMAGE |
VARCHAR2(3) |
Indicates whether the column data is in release 8.0 image format (YES ) or not (NO ) |
|
DATA_UPGRADED |
VARCHAR2(3) |
Indicates whether the column data has been upgraded to the latest type version format (YES ) or not (NO ) |
|
HISTOGRAM |
VARCHAR2(15) |
Indicates existence/type of histogram:
|
Footnote 1 These columns remain for backward compatibility with Oracle7. This information is now in the {TAB
|PART
}_COL_STATISTICS
views.