Question to SAP: What does the H stand for in hdb....?

Now that HANA 1.0 reached GA status I was reading the "SAP In-Memory Database - Server Installation and Update Guide". In this guide I see the prefix "hdb" all over and it makes me wonder what does this hdb stand for? Is it an abbreviation for:

- HANA DB?

- Hybrid DB? (columnar storage + row storage)

- HassoDB?

- "s" was already used by MaxDB so some random letter was chosen and pure chance decided to use "h" for the IMCE

Regards,

Mark