1. Get rid of all advertisements and get unlimited access to documents by upgrading to Premium Membership. Upgrade to Premium Now and also get a Premium Badge!

Automatic Memory Management in Oracle 10g

Discussion in 'Server Administration and Options' started by Arju, Oct 10, 2008.

  1. Arju

    Arju Forum Expert

    Messages:
    107
    Likes Received:
    5
    Trophy Points:
    240
    Location:
    Bangladesh
    Automatic Memory Management in Oracle 10g

    With 10g you no longer have to think of setting the following initialization parameters:

    DB_CACHE_SIZE,
    SHARED_POOL_SIZE,
    LARGE_POOL_SIZE and
    JAVA_POOL_SIZE

    With just setting one only SGA_TARGET parameter all above parameters are autmatically sized and they will use value from SGA_TARGET as demand. This setting of only SGA_TARGET parameter to a positive value is called automatic memory management feature of oracle. And above four parameters are called automatically sized components.

    To set sga_target to 500M issue,
    Code (Text):

    [B]ALTER SYSTEM SET SGA_TARGET=500M;[/B]
     
    On the other hand,

    LOG_BUFFER,
    BUFFER_POOL_KEEP,
    BUFFER_POOL_RECYCLE,
    STREAMS_POOL_SIZE ,
    db_16k_cache_size,
    db_2k_cache_size,
    db_32k_cache_size,
    db_4k_cache_size,
    Fixed SGA and
    other internal components are manually sized components.

    If you set these parameters then it automatically reduce the value from SGA_TARGET if SGA_TARGET is set to value greater than zero.

    Suppose if we set db_16k_cache_size=50M and SGA_TARGET=500M then (500-50)=450M memory will be distributed along the automatically sized components.

    You can see the the automatically components by,
    Code (Text):
    SQL> select * from V$SGA_DYNAMIC_COMPONENTS;