Harald Fuchs <[EMAIL PROTECTED]> writes:

> In article <[EMAIL PROTECTED]>,
> Jorge Godoy <[EMAIL PROTECTED]> writes:
>
>> Harald Fuchs <[EMAIL PROTECTED]> writes:
>>> Why putting gapless numbers into the database at all?  Just calculate them 
>>> at
>>> query time.
>
>> And how would you retrieve the record that corresponds to invoice number
>> #16355, for example?  Recalculating few records is fine, but millions of them
>> everytime you need to recover some of those is something that doesn't look
>> efficient to me... 
>
> This would be
>
>   SELECT whatever
>   FROM tbl
>   ORDER BY id
>   LIMIT 1
>   OFFSET 16355 -1
>
> Since id is the primary key, this can use an index scan.

If the ID was the number yes.  I thought you were suggesting having the number
computed at "query time", not to insert the record on the table...  

-- 
Jorge Godoy      <[EMAIL PROTECTED]>

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