A BETWEEN predicate compares a value with a range of values. (B)0[m[1mbetween-predicate = [m [1m [m [1mqq> value-expr qwqqqqqqqqwq> [1;4mBETWEEN[m[1m qwqqqqqqqqqqqqqqqqwqk[m [1m mq> [1;4mNOT[m[1m qj tq> [1;4mASYMMETRIC[m[1m qqu x [m [1m mq> [1;4mSYMMETRIC[m[1m qqqj x [m [1mlqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj[m [1mmq>[m [1mvalue-expr [1;4mAND[m[1m value-expr qqqqqqqqqqqqqqqqqqqqqqqqqqq>[m See the Value_Expressions HELP topic for details on value expressions. ASYMMETRIC is the default. The BETWEEN predicate is a simpler way of representing conditions that can be represented using other conditional operators: value1 BETWEEN value2 AND value3 Using the BETWEEN predicate is the same as using the following complex predicate: value1 >= value2 AND value1 <= value3 ASYMMETRIC By default, the BETWEEN predicate depends on the ordering of the values. i.e. the first value expression needed to be less than or equal to the second value expression and was evaluated as equivalent to: V0 following example. SQL> select a from t where a between asymmetric 2 and 4; A 2 3 4 3 rows selected The following query returns zero matches because the value expressions are out of order. SQL> select a from t where a between asymmetric 4 and 2; 0 rows selected SYMMETRIC This alternate format for BETWEEN allows simpler comparision of unordered value expressions, as can be seen in these examples which return the same results. This comparision is equivalent to: (V0 For example: SQL> select a from t where a between symmetric 2 and 4; A 2 3 4 3 rows selected SQL> select a from t where a between symmetric 4 and 2; A 2 3 4 3 rows selected Note that NOT BETWEEN operation also changes when using SYMMETRIC This first query using ASYMMETRIC returns all values not in the specified range. SQL> select a from t where a not between asymmetric 2 and 4; A 1 5 2 rows selected In this next query the range values is out of order and the BETWEEN predicate returns an empty set of matches, and therefore NOT BETWEEN returns all rows in the example table. SQL> select a from t where a not between asymmetric 4 and 2; A 1 2 3 4 5 5 rows selected Contrast this to SYMMETRIC which returns the same set of values for either ordering of values: SQL> select a from t where a not between symmetric 2 and 4; A 1 5 2 rows selected SQL> select a from t where a not between symmetric 4 and 2; A 1 5 2 rows selected