ArcSDE性能优化-Oracle将数据库对象Pin到共享池中来提高数据库性能

在Oracle数据库中可以将数据库对象Pin到共享池中来提高数据库性能

PS：Pin直译为钉住、压住，个人理解为将对象放入到共享池中，因为不知道翻译什么合适，都已Pin直接描述。

建议Esri所有的存储过程和序列都被Pin，一旦对象驻留在Oracle的共享池中，他们不需要对其进行分析，从而节省大量资源。

在共享池中Pin对象所使用的可用内存可能会被其他进程占用，所以为共享池分配额外的内存是非常必要的，一般情况下，做不Pin对象很少使用 ；这可能会对数据库性能的不利影响。

执行步骤

1：在执行Pin数据库对象之前，需要将SYS用户的共享池（DBMS_SHARED_POOL)权限赋予SDE用户

GRANT execute ON dbms_shared_pool TO sde;

2：在共享池Pin对象

EXECUTE dbms_shared_pool.keep ('STANDARD', 'P');

可以对SYS用户下的以下包进行Pin 
STANDARD 

   DBMS_STANDARD 

   DBMS_UTILITY 

   DBMS_DESCRIBE 

   DBMS_OUTPUT

3：作为SDE用户，可以将频繁使用的对象进行Pin

EXECUTE dbms_shared_pool.keep ('VERSION_UTIL', 'P'); 

 EXECUTE dbms_shared_pool.keep ('LOCK_UTIL', 'P');

4：数据库对象并不限于存储过程。数据库序列、 触发器和游标可以全部PIN在共享池中。ESRI 建议PIN经常使用的序列。

EXECUTE dbms_shared_pool.keep ('SDE.CONNECTION_ID_GENERATOR', 'Q');

关于DBMS_SHARED_POOL.KEEP的解释

--  Keep an object in the shared pool.  Once an object has been keeped in
  --    the shared pool, it is not subject to aging out of the pool.  This
  --    may be useful for certain semi-frequently used large objects since
  --    when large objects are brought into the shared pool, a larger
  --    number of other objects (much more than the size of the object
  --    being brought in, may need to be aged out in order to create a
  --    contiguous area large enough.
  --    WARNING:  This procedure may not be supported in the future when
  --    and if automatic mechanisms are implemented to make this
  --    unnecessary.
  --  Input arguments:
  --    name
  --      The name of the object to keep.  There are two kinds of objects:
  --      PL/SQL objects, triggers, sequences, types and Java objects,
  --      which are specified by name, and
  --      SQL cursor objects which are specified by a two-part number
  --      (indicating a location in the shared pool).  For example:
  --        dbms_shared_pool.keep('scott.hispackage')
  --      will keep package HISPACKAGE, owned by SCOTT.  The names for
  --      PL/SQL objects follows SQL rules for naming objects (i.e.,
  --      delimited identifiers, multi-byte names, etc. are allowed).
  --      A cursor can be keeped by
  --        dbms_shared_pool.keep('0034CDFF, 20348871', 'C')
  --      The complete hexadecimal address must be in the first 8 characters.
  --      The value for this identifier is the concatenation of the
  --      'address' and 'hash_value' columns from the v$sqlarea view.  This
  --      is displayed by the 'sizes' call above.
  --      Currently 'TABLE' and 'VIEW' objects may not be keeped.
  --    flag
  --      This is an optional parameter.  If the parameter is not specified,
  --        the package assumes that the first parameter is the name of a
  --        package/procedure/function and will resolve the name.  Otherwise,
  --        the parameter is a character string indicating what kind of object
  --        to keep the name identifies.  The string is case insensitive.
  --        The possible values and the kinds of objects they indicate are
  --        given in the following table:
  --        Value        Kind of Object to keep
  --        -----        ----------------------
  --	      P          package/procedure/function
  --	      Q          sequence
  --	      R          trigger
  --	      T          type
  --          JS         java source
  --          JC         java class
  --	      JR         java resource
  --	      JD         java shared data
  --	      C          cursor
  --      If and only if the first argument is a cursor address and hash-value,
  --        the flag parameter should be set to 'C' (or 'c').
  --  Exceptions:
  --    An exception will raised if the named object cannot be found.

文章来源：http://resources.arcgis.com/zh-cn/content/kbase?fa=articleShow&d=20504