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Re: Query Is to Slow
Posted by: Rick James
Date: October 30, 2012 11:48AM

OR is often a performance killer. Sometimes UNION is the solution:

select  distinct concat(users.first_name, " ", users.last_name) as Name
    from  users
    left join  tasks on users.id = tasks.created_by
    where  (tasks.date_start between @start and  @stop)
    order by  concat(users.first_name, " ", users.last_name) ;
UNION DISTINCT
select  distinct concat(users.first_name, " ", users.last_name) as Name
    from  users
    left join  meetings on users.id = meetings.created_by
    where  (meetings.date_start between @start and  @stop)
    order by  concat(users.first_name, " ", users.last_name) ;

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October 29, 2012 05:47AM
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