ALL_TAB_COLUMNS

ALL_TAB_COLUMNS describes the columns of all tables, views, and clusters accessible to the user. To gather statistics for this view, use the SQL command ANALYZE.

Related views:

• DBA_TAB_COLUMNS describes the columns of all tables, views, and clusters in the database.

• USER_TAB_COLUMNS describes the columns of all 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	Table, view, or cluster name
  COLUMN_NAME	VARCHAR2(30)	NOT NULL	Column name
  DATA_TYPE	VARCHAR2(30)		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.
  COLUMN_ID	NUMBER	NOT NULL	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		These columns remain for backward compatibility with Oracle7. This information is now in the {TAB|PART}_COL_STATISTICS views. This view now picks up these values from HIST_HEAD$ rather than COL$.
  LOW_VALUE	RAW(32)
  HIGH_VALUE	RAW(32)
  DENSITY	NUMBER
  NUM_NULLS	NUMBER		The number of nulls in the column
  NUM_BUCKETS	NUMBER		The number of buckets in histogram for the column
  LAST_ANALYZED	DATE		The date on which this column was most recently analyzed
  SAMPLE_SIZE			The sample size used in analyzing this column
  CHARACTER_SET_NAME	VARCHAR2(44)		The name of the character set: CHAR_CS or NCHAR_CS
  CHAR_COL_DECL_LENGTH	NUMBER		The 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)		Were the statistics entered directly by the user?
  AVG_COL_LEN	NUMBER		The average length of the column, in bytes