I have a tutorial available to understand how one can use Berkeley DB
to store data with multiple fields [1]. If you are only interested in
understanding how to do look up by one or more of them, please skip to
slide 51.
If this doesn't help, I can write up another explanation for the
issues that are outstanding.
Hope this helps.
Nikunj
http://o-micron.blogspot.com
[1]
http://www.oracle.com/technology/products/berkeley-db/tutorial-berkeleydb-ds.html
On Jun 26, 2009, at 1:13 PM, Maciej Stachowiak wrote:
It's also not clear to me if a BDB-level API is sufficient for
developer needs. As I understand it, it's basically a giant
dictionary with unstructured keys and values. So it's not
providing much over LocalStorage, except for prefix matching and
the ability to hold large amounts of records or records that are
individually large. There's no way to efficiently query by one of
several fields, as I understand it.
I trust that you are relatively new to storing data with B-trees.
They are at the heart of Oracle's indices so efficiency is out of
question. If you are wondering how can people store complex data
items with multiple fields and repeating values, look at Berkeley
DB Java Edition, which supports the EJB 3 persistence model [5].
FYI, there is no significant difference between the APIs of BDB
Java Edition and the original BDB. They also have identical
licensing requirements.
Your references do not appear to explain on a technical level how
one stores data with multiple fields in a way that you can query
efficiently by more than one of them. I would appreciate a brief
explanation.
