Hibernate infers the arguments in the cases they are not defined and passes them along to the database. For example, say you have the following in HQL/JPQL:

trim (' word ')

Hibernate implies:

• BOTH as the "trim spec"
• ' ' as the "trim character"
• (and always uses FROM)

and functionally passes along to the database (well the Dialect function):

trim( BOTH ' ' FROM ' word ' )

In other words, we always have 4 arguments for TRIM calls. We choose these as the implied values, because that's what JPA says the implied values are (JPA 2.1, section 4.6.17.2.1).

That's why I wanted to see a test that shows this failing.