Re: Indexes with few values

Mats Larsson wrote:
>
> Suppose I have a table where one of the columns has only three
> different values :
>
> null 1 miljon rows
> 'J' 1 miljon rows
> 'N' 0 - 100 rows.
>
> If I want to search for rows with the value 'N' then an index would help
> wouldn't it ?

  It depends on whether you have set an index on the column withe the value 'N'. Besides, there are other factors to affect the execution plan. For instance, your tuning strategies.

  Related Topics: Constraints, Cost-based approach, Rule-based approach, SQL parsing

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