ALL_TAB_COLUMNS

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.

Related Views

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 column^Foot 1
`LOW_VALUE`	`RAW(32)`		Low value in the column^Footref 1
`HIGH_VALUE`	`RAW(32)`		High value in the column^Footref 1
`DENSITY`	`NUMBER`		Density of the column^Footref 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 `SIZE` parameter of the SQL statement `ANALYZE`. However, the Oracle Database does not create a histogram with more buckets than the number of rows in the sample. Also, if the sample contains any values that are very repetitious, the Oracle Database creates the specified number of buckets, but the value indicated by this column may be smaller because of an internal compression algorithm.
`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` `VARCHAR2` `NCHAR` `NVARCHAR`
`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: `CHAR` `VARCHAR2` `NCHAR` `NVARCHAR2`
`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: `NONE` `FREQUENCY` `HEIGHT BALANCED`

^Footnote 1These columns remain for backward compatibility with Oracle7. This information is now in the {TAB|PART}_COL_STATISTICS views.