Hi,
I''m indexing records from different database tables and they
have
identical column names in many cases. Does this mean I have to create
different indexes for each table?
TIA,
Vamsee.
Not necessarily. If you index the table name as a separate field for each document added to the index, it can be used (as a TermQuery clause) to constrain searches for just documents from a specific table. The acts_as_ferret posted to the Ferret wiki does this, for example. Erik On Jan 2, 2006, at 7:20 AM, Vamsee Kanakala wrote:> Hi, > > I''m indexing records from different database tables and they > have > identical column names in many cases. Does this mean I have to create > different indexes for each table? > > TIA, > Vamsee. > _______________________________________________ > Ferret-talk mailing list > Ferret-talk at rubyforge.org > http://rubyforge.org/mailman/listinfo/ferret-talk
Erik Hatcher wrote:>Not necessarily. If you index the table name as a separate field for >each document added to the index, it can be used (as a TermQuery >clause) to constrain searches for just documents from a specific >table. The acts_as_ferret posted to the Ferret wiki does this, for >example. > >Thanks, Erik. That raises the obvious question I should''ve asked before - which is a better approach and which is faster? TIA, Vamsee.
On Tue, Jan 03, 2006 at 06:05:31PM +0530, Vamsee Kanakala wrote:> Erik Hatcher wrote: > > >Not necessarily. If you index the table name as a separate field for > >each document added to the index, it can be used (as a TermQuery > >clause) to constrain searches for just documents from a specific > >table. The acts_as_ferret posted to the Ferret wiki does this, for > >example. > > > > > Thanks, Erik. That raises the obvious question I should''ve asked before > - which is a better approach and which is faster?Imho this depends on how your queries look like. If you want to run queries across all tables, having only one index should be faster because no merging of results from different indexes has to take place. On the other hand, if you want to query only data of one of your tables, having a dedicated index for that table should be faster. But unless you have huge amounts of data in your indexes, in practice the difference in speed won''t matter. At least that''s what I experienced with Java lucene. Jens -- webit! Gesellschaft f?r neue Medien mbH www.webit.de Dipl.-Wirtschaftsingenieur Jens Kr?mer kraemer at webit.de Schnorrstra?e 76 Telefon +49 351 46766 0 D-01069 Dresden Telefax +49 351 46766 66