Re: Query-Performance

The only reason I can find is that ...when you use wildcards like % then ..
Oracle uses index only on strings searches like '%str' not on the string searches like '%str%'. Can you please send the explain plan output ? So that we will be able to find out exactly where the problem is ??

vijay

wolfgang.behrentin_at_passo.de (Wolfgang B.) wrote in message news:<341b99d7.0305130015.177a5dfc_at_posting.google.com>...
> Hello
> I am wondering about a problem i have in a database that i can't
> reconstruct.
> We have an db for looking up POI's (Points of Interest like Hotels,
> ...) or Address-Information. e.g return all hotels that match '%ba%'
> in Berlin or give me all Streets in London that match '%back%' like
> back-street or street-backery.
>
> Everything is running well but in certain and very few cases, the
> query takes instead of centi-seconds 20 or more seconds. That happens
> when someone looks up name like '%the%' or '%back%'. I cant figure out
> a difference between these names and names like ''%str%' which also
> have a very low kardinality in the database.
> The search is done without Spatial nor Intermedia using regular
> b-tree-indexes. (category-id,longitude,latitude,name,poi-id).
>
> Any idea?
> Wolfgang
Received on Tue May 13 2003 - 17:43:18 CEST