There are two methods to determine whether Windows Server 2003 you are running is a 32-bit or a 64-bit version.
| Method 1: View System Properties in Control Panel
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Method 2: View System Information window
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Notes
| Property | Description |
| Parameter type | Big integer |
| Syntax |
|
| Default value | 10 MB or 20% of the size of the SGA, whichever is greater |
| Modifiable |
|
| Range of values | Minimum: 10 MB Maximum: 4096 GB - 1 |
| Basic | Yes |
PGA_AGGREGATE_TARGET specifies the target aggregate PGA memory available to all server processes attached to the instance.
Setting PGA_AGGREGATE_TARGET to a nonzero value has the effect of automatically setting the WORKAREA_SIZE_POLICY parameter to AUTO. This means that SQL working areas used by memory-intensive SQL operators (such as sort, group-by, hash-join, bitmap merge, and bitmap create) will be automatically sized. A nonzero value for this parameter is the default since, unless you specify otherwise, Oracle sets it to 20% of the SGA or 10 MB, whichever is greater.
Setting PGA_AGGREGATE_TARGET to 0 automatically sets the WORKAREA_SIZE_POLICY parameter to MANUAL. This means that SQL workareas are sized using the *_AREA_SIZE parameters.
Oracle attempts to keep the amount of private memory below the target specified by this parameter by adapting the size of the work areas to private memory. When increasing the value of this parameter, you indirectly increase the memory allotted to work areas. Consequently, more memory-intensive operations are able to run fully in memory and less will work their way over to disk.
When setting this parameter, you should examine the total memory on your system that is available to the Oracle instance and subtract the SGA. You can assign the remaining memory to PGA_AGGREGATE_TARGET.
Note:
1. Query for the current value of the parameter
select name, value, isdefault, isses_modifiable, issys_modifiable,
isinstance_modifiable, isdeprecated, description
from v$parameter where upper(name) = ‘’;
| NAME | VALUE | IS DEFAULT | ISSES_ MODIFIABLE | ISSYS_ MODIFIABLE | ISINSTANCE_ MODIFIABLE | IS DEPRECATED | DESCRIPTION |
| Property | Description |
| Parameter type | Integer |
| Default value | 900 |
| Modifiable | ALTER SYSTEM |
| Range of values | 0 to 231 - 1 |
| Real Application Clusters | Oracle recommends that multiple instances have the same value. |
UNDO_RETENTION specifies (in seconds) the low threshold value of undo retention. For AUTOEXTEND undo tablespaces, the system retains undo for at least the time specified in this parameter, and automatically tunes the undo retention period to satisfy the undo requirements of the queries. For fixed- size undo tablespaces, the system automatically tunes for the maximum possible undo retention period, based on undo tablespace size and usage history, and ignores UNDO_RETENTION unless retention guarantee is enabled.
The setting of this parameter should account for any flashback requirements of the system. Automatic tuning of undo retention is not supported for LOBs. The RETENTION value for LOB columns is set to the value of the UNDO_RETENTION parameter.
The UNDO_RETENTION parameter can only be honored if the current undo tablespace has enough space. If an active transaction requires undo space and the undo tablespace does not have available space, then the system starts reusing unexpired undo space. This action can potentially cause some queries to fail with a "snapshot too old" message.
The amount of time for which undo is retained for the Oracle Database for the current undo tablespace can be obtained by querying the TUNED_UNDORETENTION column of the V$UNDOSTAT dynamic performance view.
| Property | Description |
| Parameter type | Big integer |
| Syntax | SGA_TARGET = integer [K | M | G] |
| Default value | 0 (SGA autotuning is disabled) |
| Modifiable | ALTER SYSTEM |
| Range of values | 64 MB to operating system-dependent |
| Basic | Yes |
SGA_TARGET specifies the total size of all SGA components. If SGA_TARGET is specified, then the following memory pools are automatically sized:
If these automatically tuned memory pools are set to nonzero values, then those values are used as minimum levels by Automatic Shared Memory Management. You would set minimum values if an application component needs a minimum amount of memory to function properly.
The following pools are manually sized components and are not affected by Automatic Shared Memory Management:
The memory allocated to these pools is deducted from the total available for SGA_TARGET when Automatic Shared Memory Management computes the values of the automatically tuned memory pools.
