Re: B+ tree: How to obtain key from value

From: <>
Date: Sun, 22 Jul 2007 05:06:08 -0700
Message-ID: <>

On Jul 14, 3:25 pm, Jonathan Leffler <> wrote:
> Dimitry wrote:
> > I am looking for solution (technique) that will allow me, while using
> > traditional B+ tree, to obtain key from value without creating
> > "reversed" table. Some overhead is acceptable but not "reversed"
> > table. Looping is also not an option.
> Homework?
> Generally, a B+Tree is an indexing structure that identifies a record.
> The record contains the key - and auxilliary data. So, you should be
> able to extract the key from the record, if you know the structure of
> the record. If you don't, you're on a hiding to nothing - there could
> be multiple keys that refer to the same data, in general, so there's no
> way to determine the key (nor, even, a key) from the value.
> --
> Jonathan Leffler #include <disclaimer.h>
> Email:,
> Guardian of DBD::Informix v2007.0226 --

What alternative would you suggest? Received on Sun Jul 22 2007 - 14:06:08 CEST

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