Thank you for the advice.
Probably, we will put index (key) on both columns.
Alex Schaft さんは書きました:
>On 2012/05/24 07:37, Alex Schaft wrote:
>> You are selecting a record based on the value of data_id and
>> thold_enabled, but don't have an index on either? Add an index for both.
>> If data_id is unique, then you would only need an index on that.
>On second thought, an index on thold_enabled won't mean much I think, so
>either leave it off or create an index on data_id plus thold_enabled.
>Someone more knowledgeable may correct me.
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