Results 1 to 3 of 3
  1. #1
    Join Date
    Jul 2004
    Posts
    2

    Smile Unanswered: Locking Strategy

    Dear Friends,

    may be that my problem has been discussed previously, but I can't find any matching thread. So please be lenient with me.

    I'm developing a VB.Net multiuser front end handling data provided by an Informix DS 9.30. Both communicate over the oledb driver which comes along with csdk 2,80.

    Now to my problem: I cannot find any substitute for the promotable lock which is easy to set in 4GL. But still I would very much appreciate to set a lock on selected rows which are only possibly going to be updated. With that any other user would be able to still have a glance at the locked data. I tried my luck with dirty read isolation level and lock mode row, but transactions are no substitute for locks since they work only with update, insert or delete statements.

    How can I set a shared lock on selected (!) rows outside any transaction frame or is there something wrong with my strategy?

    Many many thanks in advance
    Dirk

  2. #2
    Join Date
    Aug 2003
    Location
    Argentina
    Posts
    780
    Hi,

    Test if level lock of table is (row or page).
    I suggest that alter tables a lock mode (row).

    Gustavo.

  3. #3
    Join Date
    Jul 2004
    Posts
    2
    Gustavo,

    yah, I tried it lock mode row - without success.

    In my eyes the first problem is that any update or delete statement results in a lock on the entire table. Of course the IDS has to rebuild the index and consequently locks it. But in that case I have to minimize the time for any transaction. That's why transaction do not help locking selected rows (which are only promoted to be updated). I'd like to use pessimistic locking.

    The second thing is that I do not have an update cursor. So how can I put a shared lock on selected rows but keep the rest of the table unlocked? any ideas?

    Thanx
    Dirk


    Quote Originally Posted by gurey
    Hi,

    Test if level lock of table is (row or page).
    I suggest that alter tables a lock mode (row).

    Gustavo.

Posting Permissions

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