Berkeley DB

Db.key_range

						import com.sleepycat.db.*;
						public void key_range(DbTxn txnid
						Dbt key, DbKeyRange key_range, int flags)
						throws DbException;
					

Description

The Db.key_range method returns an estimate of the proportion of keys that are less than, equal to, and greater than the specified key. The underlying database must be of type Btree.

The information is returned in the key_range argument, which contains three elements of type double, less, equal, and greater. Values are in the range of 0 to 1; for example, if the field less is 0.05, it indicates that 5% of the keys in the database are less than the key argument. The value for equal will be zero if there is no matching key and non-zero otherwise.

If the operation is to be transaction-protected, ...