Initialization Parameters

Submitted by admin on Sat, 2004-08-07 07:17.

To increase I/O throughput, experiment with:
- _DB_BLOCK_WRITE_BATCH=32 (note the underscore),

- DB_BLOCK_CHECKPOINT_BATCH=32, and

- DB_FILE_MULTIBLOCK_READ_COUNT=32.
Set CHECKPOINT_PROCESS=TRUE for large databases to optimize checkpointing.
Increase TRANSACTIONS_PER_ROLLBACK_SEGMENT if you experience rollback segment header waits.
LOG_CHECKPOINT_INTERVAL should be large to minimize checkpointing but will slow down database startup (recovery takes longer than to re-generate changes).
The default SORT_AREA_SIZE is way to small increase it to at least 0.5 Meg.
Make sure PRE_PAGE_SGA=NO (the default).
TIMED_STATISTICS=YES will incur +-10% CPU overhead but can provide valuable tuning info.
DB_BLOCK_BUFFERS between 5000 and 10000 works best on MVS.
Use a really big SHARED_POOL_SIZE - 20 Meg or higher per instance - use DBMS_SHARED_POOL.SIZES() to monitor large objects. Fragmentation will be severe. Oracle doesn't cleanup/compress this area.
The DYNWORK= parameter in MPMPARMS should be at least 12 but might cause inadequate resource consumption when to high (CPU idle with lots of work waiting).
If your network is unstable and you experience lots of TX lock requests in V$LOCK, increase CLEANUP_ROLLBACK_ENTRIES.