value-expr A value expression. A symbol or a string of symbols used to calculate a value. When you use a value expression in a statement, Oracle Rdb calculates the value associated with the expression and uses that value when executing the statement. match-expr A match expression. An expression in quotation marks that is used to match a pattern. Use the double quote character (") in C programs. Use the single quote character (') in Pascal programs. The match expression can include the following special symbols (called wildcards): o * Matches a string of zero or more characters that maps onto its position o % Matches a single character that maps onto its position