Github user buptljy commented on the issue:
https://github.com/apache/flink/pull/5638
@walterddr As explained in
[FLINK-8930](https://issues.apache.org/jira/browse/FLINK-8930), the reason that
"LOG(-1)" and "LOG(1, 100)" succeed is that they're simplified in calcite's
evaluation, while "testTableApi" doesn't have the same process. And that's why
I fail to write "testTableApi" for function "LOG".
If you change "LOG(1, 100)" to "LOG(f30, 100)" which makes calcite unable
to simplify it, you will get the same error as I get in writing "testTableApi".
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