Suggested parameter settings – Oracle Audio Technologies ORACLE9I B10508-01 User Manual

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Suggested Parameter Settings

Oracle9i 64-bit Feature


sections that are not backed by any file


These global sections are not pageable and

do not require a backing file.

Suggested Parameter Settings


Big Oracle Blocks (BOB) provide the ability to support larger I/O transfers
between memory and disk


BOB complements large SGA configurations,

because BOB allows the system to move data faster between memory and disk


With VLM configurations, system performance depends directly on the ability
of the system to move database blocks into the SGA as efficiently as possible


Without the benefits of improved data transfer, performance can decline.

For a pure decision support system (DSS) application, you may wish to choose
a large value (such as 32K) for DB_BLOCK_SIZE


For an OLTP type of

application, choose a lower value (such as, 2K or 4K)


The larger the DB_

BLOCK_SIZE, the more serious the impact on single-row lookups.


Configure the size of the Oracle buffer cache such that it will provide the best
possible cache hit ratio without affecting memory requirements of other Oracle
and system processes.

For example, for a 3 GB buffer cache, with DB_BLOCK_SIZE=8192, set DB_


To enable Cost Based Optimizer (CBO), set:

optimizer_mode = choose

To use CBO, make sure all the tables and indexes are analyzed so that the
statistics are up-to-date


Use the SQL*Plus commands "analyze ...estimate" for

large tables and "analyze index ... compute statistics" for indexes.


Set the SORT_AREA_SIZE parameter with care



space used in Program Global Area (PGA) for each sort executed by each Oracle


If the value is too high, the PGA will use excessive memory when



The default value (512 K) is usually sufficient.


When no statistics are gathered or available, the Rule-based

Optimizer (RBO) is used.


Ensure the query does not use the rule hint (/*+ rule */)


Otherwise the CBO will be disabled.