help on the performance based queries

  • Hi,

    I need the help to solve the below mentioned questiones.

    1. <>. > =. LIKE what is the order as per performance

    2. select * from tab1 where lower(name)='name' is fast or

    select * from tab1 where name='NAME' or name ='name'

    out the these two queries which is fast?

    3. Restore DB from 2000 to 7 is possible?

    4. order by, union, select distinct, all these are used sorting the rows.

    Regards,

    Naveen

  • Can anyone give the solutins for the mentioned 4 points in the previous

    Regards,

    Naveen

  • ekknaveen (3/24/2010)


    1. <>. > =. LIKE what is the order as per performance

    Didnt get this , what you want here ?

    2. select * from tab1 where lower(name)='name' is fast or

    select * from tab1 where name='NAME' or name ='name'

    out the these two queries which is fast?

    lower(name) will force sql optimizer no to go for seek give bad performance

    4. order by, union, select distinct, all these are used sorting the rows.

    union and distinct not used for sorting.better google these keywords one by one

    -------Bhuvnesh----------
    I work only to learn Sql Server...though my company pays me for getting their stuff done;-)

  • ekknaveen (3/24/2010)


    Hi,

    I need the help to solve the below mentioned questiones.

    1. <>. > =. LIKE what is the order as per performance

    2. select * from tab1 where lower(name)='name' is fast or

    select * from tab1 where name='NAME' or name ='name'

    out the these two queries which is fast?

    3. Restore DB from 2000 to 7 is possible?

    4. order by, union, select distinct, all these are used sorting the rows.

    Regards,

    Naveen

    This sounds like interview questions. Are they?

    4. I'm not sure I understand what you're asking.

    The others, answers are possible, but not if I'm helping you scam an interview.

    "The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood"
    - Theodore Roosevelt

    Author of:
    SQL Server Execution Plans
    SQL Server Query Performance Tuning

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