When setting hibernate.boot.allow_jdbc_metadata_access=false, the dialect is supposed to default to the minimum supported version, but it apparently defaults to 0.0.0, leading to this warning:

09:10:52,540 WARN Dialect:354 - HHH000511: The 0.0.0 version for [org.hibernate.dialect.OracleDialect] is no longer supported, hence certain features may not work properly. The minimum supported version is 19.0.0. Check the community dialects project for available legacy versions.

This happens regardless of whether one uses hibernate.dialect or jakarta.persistence.database-product-name to select the dialect.