LARGE_POOL_SIZE

[smdakram]

!HAI

Any one can tell abort LARGE_POOL_SIZE ,

How these storage structure is use.

i want to know how these large_pool will use in ORACLE.


THANKS

[dknight]

Large Pool is used for I/O slave processes with RMAN. It improves performance by offering extra buffer space.

You can size the large pool with

LARGE_POOL_SIZE
LARGE_POOL_MIN_ALLOC

parameters in init.ora

If the size is 0, the large pool is not set.

Good luck.

[nabaig]

Also used for:

Session memory for MTS.
Parallel execution when PARALLEL_AUTOMATIC_TUNING parameter is set to true.

[tamilselvan]

LARGE_POOL_SIZE does not improve I/O slave processes.
If this area is set, then it will be used for PL/SQL procedures.
In general, 10 % of SHARED_POOL_SIZE is set for this parameter.
If your application has more procedures and functions, then set this value to high.

[Edited by tamilselvan on 10-01-2001 at 03:49 PM]

[jmodic]

Originally posted by tamilselvan
LARGE_POOL_SIZE does not improve I/O slace processes.
If this area is set, then it will be used for PL/SQL procedures.
In general, 10 % of SHARED_POOL_SIZE is set for this parameter.
If your application has more procedures and functions, then set this value to high.

I beg to differ, the abowe is all wrong. Large pool is not a part of SHARED POOL and has nothing to do with it, so comparing its size with SHARED_POOL_SIZE is irrelevant. Shared pool is totaly separate part of SGA, and as stated in some previous answers, plays its role in any of the following areas:
- sesion memory for MTS configuratins
- inter process comunication for parallel executions
- disk I/O buffers for RMAN

You will not find any PL/SQL procedure in a LARGE_POOL.

[tamilselvan]

Modic,

I agree with you one point. LARGE_POOL_SIZE does improve I/O Subsystem process particulary on Tape writing. It was my mistake.

I did not say that LARGE_POOL_SIZE is within SHARED_POOL_SIZE. What I said 10% of SHARED_POOL_SIZE can be set for LARGE_POOL_SIZE.
In general Oracle uses LARGE_POOL_SIZE for loading a large PL/SQL block. The minimum setting is 300K, but the setting must also be big as the LARGE_POOL_MIN_ALLOC, which is the minimum size of SHARED POOL memory requested that will force an allocation in the LARGE_POOL_SIZE memory.

You will find PL/SQL BLOCK in LARGE POOL memory.

[julian]

Shared pool is totaly separate part of SGA, and as stated in some previous answers, plays its role in any of the following areas:
- sesion memory for MTS configuratins
- inter process comunication for parallel executions
- disk I/O buffers for RMAN

I will add also Oracle*XA.

[julian]

Originally posted by tamilselvan
Modic,

I agree with you one point. LARGE_POOL_SIZE does improve I/O Subsystem process particulary on Tape writing. It was my mistake.

I did not say that LARGE_POOL_SIZE is within SHARED_POOL_SIZE. What I said 10% of SHARED_POOL_SIZE can be set for LARGE_POOL_SIZE.
In general Oracle uses LARGE_POOL_SIZE for loading a large PL/SQL block. The minimum setting is 300K, but the setting must also be big as the LARGE_POOL_MIN_ALLOC, which is the minimum size of SHARED POOL memory requested that will force an allocation in the LARGE_POOL_SIZE memory.

You will find PL/SQL BLOCK in LARGE POOL memory.

LARGE_POOL_MIN_ALLOC is used to avoid fragmentation. All large pool chucks are rounded up to _LARGE_POOL_MIN_ALLOC which is 16K by default.

And, tamilselvan is right, jmodic is wrong: the Large Pool hadles for example the big Designer PL/SQL packages.