Property | Description |
---|---|
Parameter type |
Big integer |
Syntax |
|
Default value |
If If If For considerations when dealing with database instances using Oracle ASM, see "SHARED_POOL_SIZE and Automatic Storage Management". |
Modifiable |
|
Range of values |
Minimum: the granule size Maximum: operating system-dependent |
Basic |
No |
SHARED_POOL_SIZE
specifies (in bytes) the size of the shared pool. The shared pool contains shared cursors, stored procedures, control structures, and other structures. If you set PARALLEL_AUTOMATIC_TUNING
to false
, then Oracle also allocates parallel execution message buffers from the shared pool. Larger values improve performance in multiuser systems. Smaller values use less memory.
You can monitor utilization of the shared pool by querying the view V$SGASTAT
.
See Also:
Oracle Database Performance Tuning Guide for more information on setting this parameter
Oracle Database Upgrade Guide for information on parallel execution message buffers
"PARALLEL_AUTOMATIC_TUNING" and "V$SGASTAT"
SHARED_POOL_SIZE and Automatic Storage Management
On a database instance using Oracle Automatic Storage Management (Oracle ASM), additional memory is required to store extent maps. As a general guideline, you can aggregate the values from the following queries to obtain current database storage size that is either already on Oracle ASM or will be stored in Oracle ASM. Then determine the redundancy type that is used (or will be used), and calculate the value for SHARED_POOL_SIZE
, using the aggregated value as input.
SELECT SUM(BYTES)/(1024*1024*1024) FROM V$DATAFILE; SELECT SUM(BYTES)/(1024*1024*1024) FROM V$LOGFILE a, V$LOG b WHERE a.group#=b.group#; SELECT SUM(BYTES)/(1024*1024*1024) FROM V$TEMPFILE WHERE status='ONLINE';
Additionally, keep the following guidelines in mind:
For diskgroups using external redundancy:
(Every 100G of space needs 1M of extra shared pool) + 2M
For diskgroups using normal redundancy:
(Every 50G of space needs 1M of extra shared pool) + 4M
For diskgroups using high redundancy:
(Every 33G of space needs 1M of extra shared pool) + 6M