In ByNameQualifiers, the qualifier names an event field whose value is to be matched, instead of matching by position.

The identifier must be the name of one of the event’s fields. The field’s type must be integer, decimal, float, or string. Each event field is allowed to appear only once on the left side of a by-name qualifier and the same field is not allowed in both a by-position qualifier and a by-name qualifier in the same event template.

If the qualifier is of the form Identifier = *, this means the qualifier matches all possible values of the specified event field.

If the qualifier is of the second form, using one of the relational operators < (less than), <= (less than or equal to), > (greater than), >= (greater than or equal to), and = (equal to), then the event field value is compared with the event template’s value and a match occurs when the result of the comparison is true.

If the qualifier is of the third form, using in followed by a range expression, then the field is compared against the boundary values of the range.

The expression or range expression on the right side is not allowed to refer to any of the event’s fields.

The expression or range expression is evaluated once, when the on statement containing the template is executed and its event expressions evaluated, not each time an event of the same type is processed by the correlator.