[jira] [Created] (DRILL-6368) "E" operator does not behave as documented "exponent operator"

["Paul Rogers (JIRA)" <ji...@apache.org>]

Paul Rogers created DRILL-6368:
----------------------------------

             Summary: "E" operator does not behave as documented "exponent operator"
                 Key: DRILL-6368
                 URL: https://issues.apache.org/jira/browse/DRILL-6368
             Project: Apache Drill
          Issue Type: Bug
    Affects Versions: 1.13.0
            Reporter: Paul Rogers


Consider the [opertors|http://drill.apache.org/docs/operators/] page which lists "E" as an operator:

bq. E	Prededence: left	exponentiation

This would mean that we can use "E" as our exponentiation operator. Let's try it:

{noformat}
SELECT 10E3 FROM (VALUES(1));
+----------+
|  EXPR$0  |
+----------+
| 10000.0  |
+----------+
{noformat}

It worked! 10^3 is indeed 1000. Wait, what? The result presented above is 10,000. Off by 10x....

Well. What's 10x among friends? Let's try more cases. Let's ensure the operator is, in fact, left associative:

{noformat}
SELECT 10E3E2 FROM (VALUES(1));
+----------+
|    E2    |
+----------+
| 10000.0  |
+----------+
{noformat}

Really? 10,000 ^ 2 is still 10,000?

Let's do some math:

{noformat}
SELECT (5+5)E3 FROM (VALUES(1));
+-----+
| E3  |
+-----+
| 10  |
+-----+
{noformat]

Lessee, 5 + 5 = 10. 10^3 = 1000. But the answer is 10.

Well. As an operator, it can stand alone, right? Just like +? Let's try:

{noformat}
SELECT 10 E 3 FROM (VALUES(1));
Error: PARSE ERROR: Encountered "3" at line 1, column 13.
{noforomat}

Jokes aside, it appears that the "E" symbol only works in the pattern:

{noformat}
number E number
{noformat}

That is, it is part of the scientific notation syntax common in many programming languages. It appears that the SQL parser is sloppy and kind of treats E as an operator, in very limited cases, but does not catch cases in which the usage is invalid.

The requests here are:

1. Change the documentation to not state that "E" is an exponentiation operator. (It isn't.)
2. Fix the parser so that id does not ignore bogus cases such as those shown above.



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