Professional Web Applications Themes

Looking for an experimental challenge? - Microsoft SQL / MS SQL Server

First recall your favorite answer for: What is TABLOCK for? How let's look at something BOL says: A table can be loaded concurrently by multiple clients if the table has no indexes and TABLOCK is specified. Let's see what MS Word's Thesaurus says: concurrently -- at the same time as Seems to conflect with the your favorite answer doesn't it. Nevertheless BOL could be correct. Anyone looking for an experimental challenge could try experimentally observing the correctness/incorrectness of BOL's statement. Bye, Delbert Glass...

  1. #1

    Default Looking for an experimental challenge?


    First recall your favorite answer for:
    What is TABLOCK for?


    How let's look at something BOL says:
    A table can be loaded concurrently by multiple clients
    if the table has no indexes and TABLOCK is specified.

    Let's see what MS Word's Thesaurus says:
    concurrently -- at the same time as

    Seems to conflect with the your favorite answer doesn't it.
    Nevertheless BOL could be correct.

    Anyone looking for an experimental challenge
    could try experimentally observing
    the correctness/incorrectness of BOL's statement.

    Bye,
    Delbert Glass


    Delbert Guest

  2. #2

    Default Re: Looking for an experimental challenge?

    The word TABLOCK is used in a confusing way in BOL

    On one hand it is used to designate a lock mode called Bulk Update (BU) -
    other locking modes are for example Shared, Update, or Exclusive.

    The BOL says the following about BU locks:

    <quote>
    Bulk update (BU) locks are used when bulk copying data into a table and
    either the TABLOCK hint is specified or the table lock on bulk load table
    option is set using sp_tableoption. Bulk update (BU) locks allow processes
    to bulk copy data concurrently into the same table while preventing other
    processes that are not bulk copying data from accessing the table.
    </quote>

    These locks are used by BULK INSERT or bcp

    So, a BU lock locks out all other use of the table except other Bulk
    loading.

    On the other hand, TABLOCK is used to deignate a locking granularity,
    locking granularity can be either ROWLOCK, PAGELOCK, or TABLOCK.

    Hope this makes it clearer

    /SG


    "Delbert Glass" <com> wrote in message
    news:phx.gbl... 


    Stefan Guest

  3. #3

    Default Re: Looking for an experimental challenge?

    >Hope this makes it clearer
    Thanks.
     

    I think it's us.
    We get use to implying/assuming exclusive table lock
    and just say table lock since the exclusive lock
    is typically the lock we manually work with.

    Meanwhile when BOL says table lock it is only stating
    the level of the lock which of course says nothing
    about the type of lock. And then, due to our bad habit
    we assume exclusive lock which as in this case can be wrong.
    Thus, it seems BOL's useage wouldn't be confusing
    if we were in the good habit of specifying
    lock level and lock type. That way when we seen a lock level only
    specified, we wouldn't go assuming a lock type;
    instead, we would wonder, "What lock type at this level?"
    Of course it would be nice if BOL joined us in the good habit.

    Bye,
    Delbert Glass


    "Stefan Gustafsson" <se> wrote in message
    news:uQ#phx.gbl... 
    >
    >[/ref]


    Delbert Guest

Similar Threads

  1. Challenge #30
    By Ray in forum Adobe Photoshop Elements
    Replies: 96
    Last Post: September 5th, 11:52 PM
  2. php4-4.3.2 for sid - experimental deb's
    By Andreas Schultz in forum Debian
    Replies: 0
    Last Post: July 28th, 10:50 AM
  3. [PHP-DEV] "Experimental" sockets ext?
    By Lars Torben Wilson in forum PHP Development
    Replies: 1
    Last Post: July 21st, 02:45 PM
  4. Little challenge for ya
    By Bill Ray in forum Macromedia Fireworks
    Replies: 0
    Last Post: July 11th, 09:43 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139