Monday, April 10, 2017

Fidelity - Performance Tuning Interview Questions


What is AWR, ADDM, ASH
What is the difference between AWR, ADDM
Tell a scenaio when u have used AWR
What are the different wait events
What db sequential file read, db scattered read events, and its difference.
What is a cursor.
what are its attributes
what is type , rowtype
what is bulk collect
how do u identify the limit set to bulk collect
What is the difference between btree and bitmap index.
There is an sql statement that ran fine in  the morining, but in the evening its taking long time. How do u identify the issue and tune the statement.
How do u find the difference in SQL plans of the same statement if there is a change in the SQL plan.

4 comments :

  1. Nice post. I learn something new and challenging on sites I stumbleupon everyday. It’s always helpful to read through articles from other writers and practice a little something from their websites.

    Please Read More: Download Ebook: Ultimate Guide To Job Interview Questions Answers:

    Best rgs

    ReplyDelete
  2. Hi There,


    Hip Hip Hooray! I was always told that slightly slow in the head, a slow learner. Not anymore! It’s like you have my back. I can’t tell you how much I’ve learnt here and how easily! Thank you for blessing me with this effortlessly ingestible digestible content.


    have been trying to write VB.Net Code to programmatically backup LocalDB, that is deployed by ClickOnce, using BACKUP DATABASE command in SQL. My requirement is to back-up the DB upon user request (on button click)
    As the mdf file in ClickOnce deployment lies in an obfuscated path(appdata/app/version/data/obfuscated_folder_names/database_name.mdf) I am unable to pass database name to backup command.
    When I pass database name as string in
    BACKUP DATABASE obfuscated_string TO DISK=@destination,
    I get an error message that identifier is too long (more than 128 characters).
    Alternately, when I pass database name as varchar(max) parameter,
    BACKUP DATABASE @FullPathofDatabase TO DISK=@destination
    I get an error message that the database does not exist, which is because actual database name in sys.databases is a truncated portion of physical_name in sys.master_files.
    Is there a method to back-up LocalDB, if at all or is this behaviour by design?





    Very useful post !everyone should learn and use it during their learning path.


    Many Thanks,

    ReplyDelete
  3. Greetings Mate,


    This is indeed great! But I think perhaps you are generally referring Oracle SQL, PL/SQL, Linux which is getting unsustainable.

    I need some help from you experts on this stored procedure..

    There are 4-5 batch procedures that will call this stored procedure. The batch will call the stored procedure with 'I' parameter in the beginning of the batch process. The batch will call the stored procedure with 'O' parameter at the end of the batch process. The stored procedure should write the details into the auditing table.

    But great job man, do keep posted with the new updates.


    Shukran,
    James

    ReplyDelete
  4. Olà,


    Brilliant article, glad I slogged through the Oracle SQL, PL/SQL, Linux it seems that a whole lot of the details really come back to from my past project.


    i creat a view as(see below)
    the problem is that i get dublicat rows and with UNION they are deselected,
    i dont want to use UNION ALL

    so my question is, how can i rewrite the two "select .. " to a Group by expression, Group by: YEAR, Month
    and get the same result as UNION ALL

    CREAT VIEW v_test_rerytering (.......) AS
    select
    F.ALDER
    age,
    cast(P.AR as VARCHAR2(4)) year,
    ccast((P.MANAD)as VARCHAR2(2)) month,
    cast(K.KON_KOD as VARCHAR2(50)) SEX,
    cast('Ext' as VARCHAR2(50)) R_KOD,
    F.NR_REK
    REK
    from test.Table_anstallda F join test.PERIOD P on P.PERIOD =
    F.PERIOD

    union

    select
    F.ALDER
    age,
    cast(P.AR as VARCHAR2(4)) year,
    ccast((P.MANAD)as VARCHAR2(2)) month,
    cast(K.KON_KOD as VARCHAR2(50)) SEX,
    cast('Internal' as VARCHAR2(50)) R_KOD,
    F.NR_dism
    REK
    from test.Table_anstallda F join test.PERIOD P on P.PERIOD_SN =
    F.PERIOD;


    Please keep providing such valuable information.

    Merci Beaucoup,
    Radhey

    ReplyDelete