Re: SELECT DISTINCT too slow

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От Miroslav Šulc
Тема Re: SELECT DISTINCT too slow
Дата
Msg-id 447F01BA.5040108@startnet.cz
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Ответ на Re: SELECT DISTINCT too slow  (Alvaro Herrera <alvherre@commandprompt.com>)
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It might be a good solution :-)

Thank you for your help.

Miroslav Šulc


Alvaro Herrera napsal(a):
> Miroslav ?ulc wrote:
>
>> Well, "key" is not primary key from another table. It is just a column
>> in pair "key" => "value".
>> The structure of the table is this:
>>
>> Id (primary key)
>> MRTPContactId (id of contact from table MRTPContact)
>> Key (key from pair key => value)
>> Value (value from pair key => value)
>>
>> So I want the get the list of keys used in the table.
>>
>
> The plan you get is the most efficient possible for that query.  If you
> had a table of possible keys (which should of course be FK of "Key"),
> you could get a much faster version :-)
>
>

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