Xapian discuss - Feb 2011 - collapsing by a key in a compound database

Hello all.

I have a problem with collapsing by a key in a compound database. I have
2 databases (e.g. clients and client branches), both of them have the
same attribute (with the same valueno), `client_id'.

What I need is to search in both these databases and collapse results by
`client_id' to get client IDs (set_collapse_key is used with
collapse_max=1).

The problem is that I receive 2 equal `client_id' values in the MSet
(one per database?).

Is it possible to get unique collapsed values when searching in a
compound database?

On Wed, Feb 23, 2011 at 12:14:33AM +0600, Evgeny Sizikov
wrote:
> I have a problem with collapsing by a key in a compound database. I have
> 2 databases (e.g. clients and client branches), both of them have the
> same attribute (with the same valueno), `client_id'.
> 
> What I need is to search in both these databases and collapse results by
> `client_id' to get client IDs (set_collapse_key is used with
> collapse_max=1).
> 
> The problem is that I receive 2 equal `client_id' values in the MSet
> (one per database?).
> 
> Is it possible to get unique collapsed values when searching in a
> compound database?
It shouldn't make a difference how many databases there are.

Are you sure the client_id values are completely identical byte for
byte?  No whitespace differences, nor differences in how accents are
encoded, etc.

If there really are exactly identical, a testcase would be useful.
Ideally self-contained and small enough to copy around easily.

Cheers,
    Olly