How to avoid a parallel execution in MyQDL.

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  • opt_inf_env@yahoo.com

    How to avoid a parallel execution in MyQDL.

    Hello,

    On my server users have access to MySQL database (through PHP). What I
    would like to avoid is parallel execution of commands. I mean, if one
    user run some sequence of command the sequence of commands run by
    another user should stay in query till the first sequence is finished.
    Is it possible to reach this only with the usage of "mysql_conn ect"
    in the beginning of sequence of command and "mysql_clos e" in the
    end. In another words, is it true that another user cannot make
    connection with DB and execute commands before the first user close
    connection (with "mysql_clos e")?

  • David Haynes

    #2
    Re: How to avoid a parallel execution in MyQDL.

    opt_inf_env@yah oo.com wrote:[color=blue]
    > Hello,
    >
    > On my server users have access to MySQL database (through PHP). What I
    > would like to avoid is parallel execution of commands. I mean, if one
    > user run some sequence of command the sequence of commands run by
    > another user should stay in query till the first sequence is finished.
    > Is it possible to reach this only with the usage of "mysql_conn ect"
    > in the beginning of sequence of command and "mysql_clos e" in the
    > end. In another words, is it true that another user cannot make
    > connection with DB and execute commands before the first user close
    > connection (with "mysql_clos e")?
    >[/color]
    I don't think so. I think you need to read Section 13.4 of the MySQL
    manual (MySQL Transactional and Locking Statements).

    -david-

    Comment

    • Christopher Browne

      #3
      Re: How to avoid a parallel execution in MyQDL.

      > On my server users have access to MySQL database (through PHP). What I[color=blue]
      > would like to avoid is parallel execution of commands. I mean, if one
      > user run some sequence of command the sequence of commands run by
      > another user should stay in query till the first sequence is finished.
      > Is it possible to reach this only with the usage of "mysql_conn ect"
      > in the beginning of sequence of command and "mysql_clos e" in the
      > end. In another words, is it true that another user cannot make
      > connection with DB and execute commands before the first user close
      > connection (with "mysql_clos e")?[/color]

      You might check with the vendor to see if there is some way to
      configure it to limit the number of connections. If so, then your
      process could grab all the connections, and not relinquish any until
      the vital process is complete.

      Alternatively, you might check to see if there is a way of expressly
      requesting locks on the tables which the vital process uses. If you
      start by locking them, that might accomplish the goal without fiddling
      with connections.
      --
      (reverse (concatenate 'string "moc.liamg" "@" "enworbbc") )

      If we were meant to fly, we wouldn't keep losing our luggage.

      Comment

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