Wrong precedence for "IS FALSE" and simiar expressions

Detail name	Value
Changelog Number	8216
Type	Bug
Status	Resolved
Affected Versions	Exasol 6.1.0, Exasol 6.2.rc1
Fix Versions	Exasol 6.2.0, Exasol 6.1.5
Resolution Date	2019-07-11

From Exasol 6.1.0 to Exasol 6.1.4, the expressions "IS FALSE", "IS TRUE", "IS NOT FALSE", "IS NOT TRUE", "IS UNKNOWN", and "IS NOT UNKNOWN" had the wrong precedence. This lead to syntax errors in valid queries.

Example:

CREATE SCHEMA test;
CREATE OR REPLACE TABLE t1  ( col1 INTEGER) ;

-- Error: operand in IS FALSE must be a boolean expression
SELECT 1 AS A FROM t1 WHERE col1 IN (1) IS FALSE;

Starting with Exasol 6.1.5 such queries work again as expected.

Changed behavior

Exasol uses now the correct precedence for expressions like "IS FALSE", "IS TRUE", "IS NOT FALSE", "IS NOT TRUE", " IS UNKNOWN", and "IS NOT UNKNOWN".