Re: Query-Performance

Because Oracle has to do a full table scan. It cannot use and index if you are searching for %ba%.
Jim

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"Wolfgang B." <wolfgang.behrentin_at_passo.de> 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