When I execute a query with a specified query timeout, for example via JPA :

    TypedQuery<SomeClass> query = entityManager.createNamedQuery("...some query...", SomeClass.class);
    query.setHint("javax.persistence.query.timeout", "1000");
    return query.getSingleResult();

If the query takes longer than 1s, I expect the database driver to throw an exception and hibernate to translate that exception to an instance of `org.hibernate.QueryTimeoutException`

Hibernate does honour this when dealing with Mysql.
The mysql driver throws a `com.mysql.cj.jdbc.exceptions.MySQLTimeoutException` which implements the standard jdk exception `java.sql.SQLTimeoutException` and for which Hibernate is translating to `org.hibernate.QueryTimeoutException` at https://github.com/hibernate/hibernate-orm/blob/39e576cea49c62763e651237f3666f97205406f6/hibernate-core/src/main/java/org/hibernate/exception/internal/SQLExceptionTypeDelegate.java#L66
So all is fine for Mysql.

However for PostgreSQL, the postgresql driver throws a generic exception `org.postgresql.util.PSQLException` which only implements `java.sql.SQLException` with a vendor specific sql state of `57014`.
The issue is that hibernate does not translate that exception to a QueryTimeoutException

By digging a bit into the sql exception translators, I've found this class: SQLStateConversionDelegate
It has two additional custom conversion cases to map to the QueryTimeoutException from a generic sql state error code.

To fix this issue, in order to have hibernate properly translate and rethrow QueryTimeoutException, would it be preferable to have either ?

1. Add another "or" clause to the sqlState if condition in SQLStateConversionDelegate

2. Fix the PostgreSQL95Dialect by overriding its `buildSQLExceptionConversionDelegate` method in order to implement this sqlState only for postgresql

3. Something else

For my issue, I was about to override the `buildSQLExceptionConversionDelegate` in the postgresql dialect because I thought it was less invasive. I'd be glad to propose a pull request and a test case it you think it can be assigned to a new contributor.