LARGE_POOL

LARGE_POOL_SIZE

Property	Description
Parameter type	Big integer
Syntax	`LARGE_POOL_SIZE =` `integer` `[K \| M \| G]`
Default value	`0` if both of the following are true: The pool is not required by parallel execution `DBWR_IO_SLAVES` is not set Otherwise, derived from the values of `PARALLEL_MAX_SERVERS`, `PARALLEL_THREADS_PER_CPU`, `CLUSTER_DATABASE_INSTANCES`, `DISPATCHERS`, and `DBWR_IO_SLAVES`.
Modifiable	`ALTER SYSTEM`
Range of values	300 KB to at least 2 GB (actual maximum is operating system-specific)
Basic	No

LARGE_POOL_SIZE specifies (in bytes) the size of the large pool allocation heap. The large pool allocation heap is used in shared server systems for session memory, by parallel execution for message buffers, and by backup processes for disk I/O buffers. Parallel execution allocates buffers out of the large pool only when PARALLEL_AUTOMATIC_TUNING is set to true.

Caution:

When Oracle derives a default value, it adds 250K for each session for the shared server if DISPATCHERS is configured. The final derived value also includes a port-specific amount of memory for backup I/O buffers. The total derived default value can either be too large to allocate or can cause performance problems. In that case, set LARGE_POOL_SIZE to a number sufficiently small so that the database can start.

You can specify the value of this parameter using a number, optionally followed by K or M to specify kilobytes or megabytes, respectively. If you do not specify K or M, then the number is taken as bytes.

See Also:

Oracle Database Performance Tuning Guide and Oracle Database Upgrade Guide for more information on setting this parameter