[BUG] Predicates expression containing multiple AND and OR operators evaluated with wrong order

[LantaoJin]

What is the bug?
a predicate expression containing multiple AND and OR operators does have an order of evaluation. This order is determined by precedence rules, just like in arithmetic where multiplication has higher precedence than addition.

In SQL:
AND has higher precedence than OR.
Parentheses can be used to explicitly define the desired order of operations and to override the default precedence.

Example Without Parentheses:

SELECT *
FROM employees
WHERE department = 'HR'
   OR job_title = 'Manager'
   AND salary > 50000;

In this query, the AND between job_title = 'Manager' and salary > 50000 is evaluated first, because AND has higher precedence than OR. It equals to

WHERE department = 'HR'
   OR (job_title = 'Manager' AND salary > 50000);

But in PPL, this query will be evaluated with wrong order:

source=employees
| where department = 'HR' OR job_title = 'Manager' AND salary > 50000

was evaluated to

source=employees
| where (department = 'HR' OR job_title = 'Manager') AND salary > 50000