|
The SYSCOLSTAT system view contains the column statistics, including histograms, that are used by the optimizer. The contents of this view are best retrieved using the sa_get_histogram stored procedure or the Histogram utility. The underlying system table for this view is ISYSCOLSTAT.
NOTEIf the database is encrypted, or if table encryption is enabled, the underlying system table, ISYSCOLSTAT, is also encrypted since it contains histogram information that could reveal underlying data. |
| Column name | Column type | Column constraint |
|---|---|---|
| table_id | UNSIGNED INT | NOT NULL |
| column_id | UNSIGNED INT | NOT NULL |
| format_id | SMALLINT | NOT NULL |
| update_time | TIMESTAMP | NOT NULL |
| density | FLOAT | NOT NULL |
| max_steps | SMALLINT | NOT NULL |
| actual_steps | SMALLINT | NOT NULL |
| step_values | LONG BINARY | |
| frequencies | LONG BINARY |
table_id A number that uniquely identifies the table or materialized view to which the column belongs.
column_id A number that, together with table_id, uniquely identifies the column.
format_id For system use only.
update_time The time of the last update of the column statistics.
density An estimate of the average selectivity of a single value for the column, not counting the large single value selectivities stored in the row.
max_steps For system use only.
actual_steps For system use only.
step_values For system use only.
frequencies For system use only.
PRIMARY KEY (table_id, column_id)
FOREIGN KEY (table_id, column_id) references SYS.ISYSTABCOL (table_id, column_id)