TIP: Feature request: Collation settings on connection level

[Ruslan Zasukhin]

On 19/6/07 1:01 PM, "Ruslan Zasukhin" <sunshine at public.kherson.ua> wrote:

>> now for this last example I think your suggestion works
>> TIP:
>>      you can make virtual field (Table Method) and specify
>>      for it other location, then its index will be DIFFERENT.
>>      Payment for this -- overhead to maintain this index.
>> 
>> I don't really see how I can specify for a field a collation but will
>> look into it
>> 
>> 
>> I understand your problem, but I am sure I worked with databases
>> (don't remember which one) that permitted me to define indexes for a
>> given collation and let me specify what index to use when doing a sort.
> 
> No problems here for Valentina also.
> 
> You make Table Method,
> 
>     fld2 = tbl.CreateVarCharField( "fld2", 2044, fIndexed, "fld1" )
> 
> "fld1" - is FORMULA, i.e. Value of fld2 virtual field will be
>             the same as fld1.
> 
> And now you say:
> 
>     fld2.CollationAttribute( ... )
> 
> This 2 steps effectively just create on disk ONE MORE index,
> Which now will work by this new collation.
> 
> And now you CAN CHOOSE what index to use in what query.
> In fact you do this via name of field
> 
>     ORDER BY fld1   -- German
>     ORDER BY fld2   -- French

Another TIP:

It is better even improve formula, in case if you really need German index
only for GERMAN records. May be something as:

  fld2 = tbl.CreateVarCharField( "fld2", 2044, fIndexed,
                "if( fld_lang='de', fld1, NULL )"

I.e. Formula selects only German records, all rest are NULL, and they eat
ZERO disk space and TIME in the index.


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]