MY_TAB_COL_STATISTICS

NONE: no histogram
FREQUENCY: frequency histogram
EQUI-WIDTH: equal-width histogram

MY_TAB_COL_STATISTICS displays column statistics and histogram information extracted from MY_TAB_COLUMNS. All users can access this view. This view exists in the PG_CATALOG and SYS schemas. For details about the columns, see Table 1.

**Table 1** MY_TAB_COL_STATISTICS columns
Name	Type	Description
table_name	character varying(128)	Table name.
column_name	character varying(128)	Column name.
num_distinct	numeric	Number of different values in a column.
low_value	raw	Low value in a column.
high_value	raw	High value in a column.
density	numeric	If there is a histogram on COLUMN_NAME, this column displays the selectivity of values in the histogram that span fewer than two endpoints. It does not represent the selectivity of values that span two or more endpoints. If no histogram is available on COLUMN_NAME, the value of this column is 1/NUM_DISTINCT.
num_nulls	numeric	Number of empty values in a column.
num_buckets	numeric	Number of buckets in the histogram of a column.
last_analyzed	date	Date when a column was last analyzed. After the database is restarted, data loss will occur.
sample_size	numeric	Sample size used to analyze a column.
global_stats	character varying(3)	Not supported. Its value is NULL.
user_stats	character varying(3)	Not supported. Its value is NULL.
notes	character varying(99)	Not supported. Its value is NULL.
avg_col_len	numeric	Average length of a column, in bytes.
histogram	character varying(15)	Specifies whether the histogram exists and the type of the histogram if it exists. NONE: no histogram FREQUENCY: frequency histogram EQUI-WIDTH: equal-width histogram
scope	character varying(7)	For statistics collected on any table other than global temporary tables, the value is SHARED (indicating that the statistics are shared among all sessions).
schema	character varying(64)	Name of the namespace to which the column belongs.