how you solved the problem ?

regards

2009/12/29 Fernando Medeiros <fdomds@...>

> Hi Tomek,
>
> > but query don't use this index.
> > I've tried even to force use this index: 'PLAN (tab INDEX ("TAB_IDX1"))',
> but it says: 'index > cannot be used in the specified plan'.
> > Any idea?
>
> I think it would be better to create a decimal field (or smallint /
> integer) and index this field.
> Performance would be better.
>
> Regards.
>
>
>
> 2009/12/28 tomjanczkadao <tomjancz@...>
>
> Hi
>> I need to select max from field, but using only decimal chars from this
>> field:
>>
>> Field1 varchar(20):
>> 'ab2548'
>> 'ag9887'
>> 'cd8745' ...
>>
>> I wrote SP only_decmial_char which extracts only decimal chars.
>> My query:
>> 'SELECT MAX((select result from only_decmial_char(Field1)))FROM tab'
>>
>> It works ok, returns 9887, but it's slow (it reads all records).
>> I've tried to use computed index:
>>
>> CREATE INDEX TAB_IDX1 ON TAB COMPUTED BY ((SELECT result FROM
>> only_decmial_char(Field1)));
>>
>> but query don't use this index.
>> I've tried even to force use this index: 'PLAN (tab INDEX ("TAB_IDX1"))',
>> but it says: 'index cannot be used in the specified plan'.
>>
>> Any idea?
>>
>> Regards, Tomek
>>
>>
>>
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>>
>
>
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