Hello,

does anybody can point on the persisten tree storage based on the
Berkeley DB Java edition or probably just give a hint what is a best
generic tree structure storage realisation using BDB JE?

Thank you in advance.

Regards,
/Alexander.

Alexander,

I am not sure what the goal of your application is, but you may want to
note that Berkeley DB Java Edition implements a btree internally to
store data. Because of that, it is not usually necessary for the
application itself to implement a tree data structure on top of JE.

Regards,

Linda

Hi Linda,

thank you for the information, but I need to implement linked tree on
top of some well known and well designed DB, so I do not see any way of
using internal implementation...

Regards,
/Alexander.


Linda Lee wrote:

Alexander,

Perhaps you are asking instead how a tree data structure might be
designed on top of JE. For example, you could have a class like this:


class Node {
long id;
long parentId;
....
}

The id field would the primary key and parentId field a secondary key.
Using the secondary database on parentId, all children can be iterated
by getting all duplicates for a given parentId key.

Is that more along the lines of what you are asking?

Linda

Hi Linda,

yep, and that too =)
I guess, that it can be done just like in any relational DB with a
structure mentioned by you.

I just suppose, that probably somebody already done that job and share
it or just could recomend the most efficient and "right" way of doing
that.

Regards,
/Alexander.

In that case, you may want to pose the question to the bdbje email
list, where there is more JE specific correspondence. There are
definitely users who have put a variety of data structures on top of
JE. Of course, they may feel that their applications are too specific,
and may not reply, but it's worth a shot. See
http://dev.sleepycat.com/community/discussion.html

Linda

Hi Linda,

oops - I supposed it's a shared BDB and BDB JE list, sorry.

I will transfer the theme for the pointed maillist, thank you.

Regards,
/Alexander.