Hibernate XML mapping for transforming a ternary relation to a value map as an entity class attribute

It's practically my first apprach to XML mapping with Hibernate, at least with non-basic model.

My demo pysical model (partially) would be something like:

---

SEASON:

SEA_ID: int -> PRIMARY KEY

SEA_DESCR: varchar

DAY:

DAY_ID: int -> PRIMARY KEY

DAY_NAME: varchar

DAY_DESCR: varchar

LEAGUE:

LEA_ID: int -> PRIMARY KEY

LEA_DESCR: varchar

MATCH: ---------- !! Attention, ternary relationship !! ----------

MTC_LEA_ID: int -> PRIMARY KEY, FOREIGN KEY 1 REFERENCES LEAGUE(LEA_ID)

MTC_SEA_ID: int -> PRIMARY KEY, FOREIGN KEY 2 REFERENCES SEASON(SEA_ID)

MTC_DAY_ID: int -> PRIMARY KEY, FOREIGN KEY 3 REFERENCES DAY(DAY_ID)

---

So, I have a ternary relation which I have to map in Hibernate with XML.

After researching about Hibernate and analyzing my specific problem I have chosen a solution which stores a map of Season-Days per League, restricting the access to league entities, deleting ternary and innecesary configuration and resulting in the next classes and configuration:

public class League {

   Long id;
   String description;
   private Map<Season, Day> daysPerSeason = new HashMap<Season, Day>(0);

   //    Here Constructurs, Getters and Setters

}

and XML Mapping:

<hibernate-mapping>
<class name="org.tanooki.examples.example.model.entities.League" table="LEAGUE">
    <id name="id" type="Integer" column="LEA_ID">
        <generator class="native" />
    </id>
    <property name="description" type="String">
        <column name="LEA_DESCR" />
    </property>
    <map name="daysPerSeason">
        <key column="LEA_ID"/>
        <map-key-many-to-many column="SEA_ID" class="org.tanooki.examples.example.model.entities.Season"/>
        <many-to-many column="DAY_ID" class="org.tanooki.examples.example.model.entities.Day"/>
    </map>
</class>

If I have not doing some mistake I would be able to access every day per season when I get a league entity.

But, now, at this moment, and before testing, I have two questions to solve:

1) First of all, how much clever is Hibernate regarding the naming of columns with foreign key contraints?. I mean ... in MATCH table I have a column called MTC_LEA_ID , but in LEAGUE table the related column is naming different (LEA_ID ). I'm not making explicit this relationship bettween the two names, because I have avoided the MATCH table (the ternary). I missing something?

2) About the save and delete behaviour, if first step is right or it only needs a small change, how works by default?. If I want to relate some couples of season-days to one league and execute save, the MATCH table would be updated or I need to include some cascade-type configuration?

Finally, sorry for my english and ...

Greetings