Mihai Budiu created CALCITE-6741:
------------------------------------
Summary: SqlToRelConverter.convertInToOr is unsound
Key: CALCITE-6741
URL: https://issues.apache.org/jira/browse/CALCITE-6741
Project: Calcite
Issue Type: Bug
Components: core
Affects Versions: 1.38.0
Reporter: Mihai Budiu
This function converts an expression into another expression which does not
have the same type.
The function convertInToOr has the following JavaDoc:
{code:java}
/* Converts "x IN (1, 2, ...)" to "x=1 OR x=2 OR ..." */
{code}
This is unsound when x is not nullable and the list contains NULL.
The "in" expression can never evaluate to NULL in that case, whereas the
converted expression can.
As an example, consider this test case, which is a simplified version of a test
from Sql Logic Test:
{code:sql}
SELECT CASE WHEN 1 NOT IN ( NULL, COUNT(*) ) THEN 1 END
{code}
The plan produced for this query is as follows:
{code}
LogicalProject(EXPR$0=[CASE(CAST(AND(null, <>(1, $0))):BOOLEAN NOT NULL, 1,
null:INTEGER)]), id = 202
LogicalAggregate(group=[{}], agg#0=[COUNT()]), id = 200
LogicalValues(tuples=[[{ 0 }]]), id = 160
{code}
Notice that there's a CAST(AND ...): BOOLEAN NOT NULL. Unfortunately the AND
expression as written is nullable, so this cast is unsound.
I am thinking that the correct expansion should use IS_NOT_DISTINCT_FROM
instead of EQUALS.
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
