Backport of micro-time patch to mysql 4.1


Taking into account 4.1 tree is still popular and is used on many production servers we
decided to make backport of patch to slow-log queries. The patch allows to specify time of slow queries in microseconds and is very helpful in a fight with problematic queries. 4.1 Patch is available here (The original patch was developed by Georg Richter georg at php net)



  1. says

    I patch mysql source, but it doesn’t work.

    I can not set long_query_time=0 . The least value of long_query_time – 1. If I set long_query_time=0, “SHOW VARIABLES;” show me long_query_time=1.

    And I see always seconds in slow log: Query_time: 2 Lock_time: 0 .

    How to turn on the patch?

  2. Vadim says


    It looks like you are still using unpatched mysqld.

    The procedure is:
    get sources
    patch with: patch -p1 < patch.slow-micro.4.1.21.diff
    ./configure –prefix=/usr/local/mysql-micro …other-options..
    make install

    In /usr/local/mysql-micro you should get binary

  3. says

    I do it again, how you write.
    After I run slow query and get this:

    # Time: 061010 0:58:54
    # User@Host: root[root] @ localhost []
    # Query_time: 7 Lock_time: 0 Rows_sent: 1 Rows_examined: 227073
    use mindmix;
    SELECT SQL_CALC_FOUND_ROWS * FROM `topics` WHERE `forum_id` !=1 LIMIT 1;

    Do you have another ideas?

  4. peter says


    Good you’ve found the problem. Regarding query you have in your example it is slow because of SQL_CALC_FOUND_ROWS – it effectively negates the limit.

Leave a Reply

Your email address will not be published. Required fields are marked *