The oracle database have a houndres of hidden parameters, that a lot of those parameters are not documented.
Know about those parameters are important for dbas involved in database migrations and upgrades.
Many parameters have a high performance improve on different systems.
set line 150
col PARAMETER format a30
col DESCRIPTION format a60
col SESSION_VALUE format a10
col INSTANCE_VALUE format a10
SELECT a.ksppinm AS parameter,
a.ksppdesc AS description,
b.ksppstvl AS session_value,
c.ksppstvl AS instance_value
FROM x$ksppi a,
WHERE a.indx = b.indx
AND a.indx = c.indx
AND a.ksppinm LIKE '/_%' ESCAPE '/'
ORDER BY a.ksppinm;
Now, after we save this list, is possible that we need started with an planificated change.
Hidden ParameHow can I set the value of a hidden parameter?
alter system set "_report_capture_cycle_time"=0 scope=spfile sid='*';
Remember, the importance that these parameters must be recommendations of the oracle support, because it can change the behavior of the engine and can leave us in the situation of not having support.
It’s a minimal post to share this option to start, stop and restart the oracle databases as linux services.
If you remember on my last article oracle installation, we used the file oracledb_ORCLCDB-19c to configure and install the databases and containers, we will use the same script as operating system service.
We must run this script as root user ever, because will appear error as the follow:
You must be root user to run the configurations script. Login as root user and try again.
I’m come back to share the last recently news about the Oracle Databases.
Oracle Database 19c is the long-term support version of the Oracle Database 12c and 18c family of products, which is available to Premier and Extended Support customers through March 2023 and March 2026, respectively.
It is available on Linux, Windows, Solaris, HP / UX and AIX platforms, as well as Oracle Cloud.
Oracle Database 19c offers customers the best performance, scalability, reliability and security for all their analytical and operational workloads.
Here, you have an small explanation about each parameter :
SESSIONS_PER_USER: The user can have any number of concurrent sessions.
CPU_PER_SESSION: In a single session, the user can consume an unlimited amount of CPU time.
CPU_PER_CALL: A single call made by the user cannot consume more than 30 seconds of CPU time.
CONNECT_TIME: A single session cannot last for more than 45 minutes.
LOGICAL_READS_PER_SESSION: In a single session, the number of data blocks read from memory and disk is subject to the limit specified in the DEFAULT profile.
LOGICAL_READS_PER_CALL: A single call made by the user cannot read more than 1000 data blocks from memory and disk.
PRIVATE_SGA: A single session cannot allocate more than 15 kilobytes of memory in the SGA.
COMPOSITE_LIMIT: in a single session, the total resource cost cannot exceed 5 million service units. The formula for calculating the total resource cost is specified by the ALTER RESOURCE COST statement.
Those are not the only paramters ,but this its a great example to start diferent tests.