Hi, >> I'm actually at a loss for what a non-primary key >> actually means at all (hint for creating an index, perhaps?) > > > This is very understandable since all databases use terminology > carelessly and without much thought put into overall conceptual > integrity. > That being said I think the relational theory does not have a concept > of non-unique key. > > And of course of primary keys (that is just a candidate key picked out > as the most representative of them) and foreign keys. > > So what could a key without the property of uniqueness possibly mean? > You are quite right at pointing out that it could be interpreted as an > alias for index.
Alternative, candidate, secondary keys, etc. are all concepts of database analysis/design. And partitioning, sharding, order keys, etc. are implementation details of physical database organization. At last their implementations vary from dbm to dbm, but the a common incarnation of that concepts are INDEXES variants. The most common (and usable) are INDEX and UNIQUE INDEX , this one is often used to incarnate a alternative KEY , even if isn't an constraint as in many dbms. regards, Dario -- You received this message because you are subscribed to the Google Groups "H2 Database" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/h2-database?hl=en.
