Re: longest prefix match

On Wed, 20 Feb 2008, Jorge Godoy wrote:

> Em Wednesday 20 February 2008 05:55:07 Dragan Zubac escreveu:
>>
>> Anybody got any ideas/experiences/links for 'longest prefix match'
>> solution in PostgreSQL ?
>> Basically,put some telephone prefices in some kind of trie,and be able
>> to perform fast lookups ?
>
> Prefix or suffix?
>
> For prefix you can use "SELECT number FROM table WHERE number LIKE '123%'".
>
> For suffix you change the "%" to the beginning of the string, but then loose
> the ability to use indices. (Unfortunately, using suffixes is really
> interesting for caller IDs since you don't always receive area code, country
> code, etc.)

you can maintain an additional index for terms backwards.

>
>

Regards,
Oleg
_____________________________________________________________
Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
Sternberg Astronomical Institute, Moscow University, Russia
Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
phone: +007(495)939-16-83, +007(495)939-23-83