oracle10g 知识篇

oracle10g 知识篇

1.Oracle10g帐户被自动锁定问题.

SQL> connect / as sysdba;
Connected.
SQL> ALTER PROFILE DEFAULT LIMIT
2 FAILED_LOGIN_ATTEMPTS UNLIMITED;

Profile altered.

2.10.2.0.1 Memory Notification: Library Cache Object loaded into SGA

Subject: Memory Notification: Library Cache Object Loaded Into Sga
Doc ID: Note:330239.1 Type: PROBLEM

Applies to:
Oracle Server - Enterprise Edition - Version:
This problem can occur on any platform.
Symptoms
The following messages are reported in alert.log after 10g Release 2 is installed.
Memory Notification: Library Cache Object loaded into SGA
Heap size 2294K exceeds notification threshold (2048K)
Changes
Installed / Upgraded to 10g Release 2
Cause
These are warning messages that should not cause the program responsible for these errors to fail. They appear as a result of new event messaging mechanism and memory manager in 10g Release 2. The meaning is that the process is just spending a lot of time in finding free memory extents during an allocate as the memory may be heavily fragmented. Fragmentation in memory is impossible to eliminate completely, however, continued messages of large allocations in memory indicate there are tuning opportunities on the application. The messages do not imply that an ORA-403X is about to happen.

Solution
In 10g we have a new undocumented parameter that sets the KGL heap size warning threshold. This parameter was not present in 10gR1. Warnings are written if heap size exceeds this threshold.

Set _kgl_large_heap_warning_threshold to a reasonable high value or zero to prevent these warning messages. Value needs to be set in bytes.

If you want to set this to 8192 (8192 * 1024) and are using an spfile:

(logged in as "/ as sysdba")

SQL> alter system set "_kgl_large_heap_warning_threshold"=8388608 scope=spfile ;

SQL> shutdown immediate SQL> startup

SQL> show parameter _kgl_large_heap_warning_threshold
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
_kgl_large_heap_warning_threshold integer 8388608

If using an "old-style" init parameter,

Edit the init parameter file and add

_kgl_large_heap_warning_threshold=8388608
In 10.2.0.2, the threshold is increased to 50MB after regression tests, so this should be a reasonable and recommended value.

请看：

Symptoms：
The following messages are reported in alert.log after 10g Release 2 is installed.
Memory Notification: Library Cache Object loaded into SGA
Heap size 2294K exceeds notification threshold (2048K)
--该情况一般发生在10.2.0.1中，因为_kgl_large_heap_warning_threshold这个版本中的缺省设置太小了。如果升级到10.2.0.2,则该情形可避免。因为它的缺省是50M，而不是2M。