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Friday, May 23, 2008

OraPerf : Oracle Free Performance Monitor

Some of the program I did during my free time. This is a the first program in Visual Basic Express using Oracle connection string.


Most Oracle DBA have to face question like
  • In general, how well is my database running? What defines efficiency?
  • What average response time are my users experiencing?
  • OraPerf is a little tool which captures Oracle database information such as session and memory usage. It is based on Oracle 10g Dynamic views V$. The information will be update every seconds.

    http://download.cnet.com/OraPerf/3000-10254_4-10816959.html

    Update :
    • Include response time metrics
    Get it from CNET Download.com!
     

    Monday, May 12, 2008

    Oracle Wait Interface v$view

    Oracle Wait Interface

    Oracle Wait Interface has had the following four V$ views :

    • V$EVENT_NAME
    • V$SESSION_WAIT
    • V$SESSION_EVENT
    • V$SYSTEM_EVENT

    For 10g

    Oracle Database 10g Release 1 introduces the following new views to display wait information from several perspectives:

    • V$SYSTEM_WAIT_CLASS
    • V$SESSION_WAIT_CLASS
    • V$SESSION_WAIT_HISTORY
    • V$EVENT_HISTOGRAM
    • V$ACTIVE_SESSION_HISTORY

    V$EVENT_NAME

    It is a reference view that contains all the wait events defined for your database instance

    select event#, name, parameter1, parameter2, parameter3 from v$event_name order by name;

    V$SESSION_WAIT

    The V$SESSION_WAIT view provides detailed information about the event or resource that each session is waiting for. This view contains only one row of information per session, active or inactive, at any given time. Unlike the other views, this view displays session-level wait information in real time.

    V$SYSTEM_EVENT

    The V$SYSTEM_EVENT displays aggregated statistics of all wait events encountered by all Oracle sessions since the instance startup. It keeps track of the total number of waits, total timeouts, and time waited for any wait event ever encountered by any of the sessions.

    select b.class, a.*, c.startup_time
    from v$system_event a,
    v$event_name b,
    v$instance c
    where a.event = b.name
    order by b.class, a.time_waited;

    V$SESSION_EVENT

    The V$SESSION_EVENT view contains aggregated wait event statistics by session for all sessions that are currently connected to the instance. This view contains all the columns present in the V$SYSTEM_EVENT view and has the same meaning, but the context is session-level. It keeps track of the total waits, time waited, and maximum wait time of each wait event by session.

    break on sid skip 1 dup
    col sid format 999
    col event format a39
    col username format a6 trunc
    select b.sid,
    decode(b.username,null,
    substr(b.program,18),b.username) username a.event,
    a.total_waits,
    a.total_timeouts,
    a.time_waited,
    a.average_wait,
    a.max_wait,
    a.time_waited_micro
    from v$session_event a, v$session b
    where b.sid = a.sid + 1

    order by 1, 6;