This is the first of my three-part series dealing with Shared servers: Today an organization can have hundreds or thousands of users connecting to their databases. The traditional dedicated server model maps each user to a dedicated process running on the database server. Each dedicated server process requires memory and as the number of users increase, there is a linear increase in the demand for memory.
The Redo Logfile Size Advisor can be used to determine the least optimal online redo log file size based on the current FAST_START_MTTR_TARGET setting and MTTR statistics.
Which means that Redo Logfile Size Advisor is enabled only if FAST_START_MTTR_TARGET is set.
The Advisor provides a recommended optimal smallest online redo log file size.
we can then adjust the online redo log file size to the recommended optimal size ,eliminating the need to manually determine an optimal size.
To use the advisor we need to query the V$INSTANCE_RECOVERY VIEW.
If our redo log file size is under sized then the checkpoint process is driven by WRITES_LOGFILE_SIZE i.e. its driven by the smallest redo log file size.
Automatic Work Load Management
Application workloads can be defined as services so that they can be individually managed and controlled.
We can control and monitor which processing resources are allocated to each service during both normal operations and in response to failures.
Performance metrics are tracked by service and thresholds set to automatically generate alerts should these thresholds be crossed.
CPU resource allocations and resource consumption controls are managed for services using Resource Manager.
we deifne rules to automatically allocate processing resources to services. Oracle RAC 10g instances can be allocated to process individual services or multiple services as needed.
When you setup statspack with level 6 you can have information on the sql_plan associated with a sql. (statpack on oracle db version >=9i)
How does one change Oracle's SYS password without having to login into the database? Is it possible?
The answer is, YES! All you need is a binary fiile editor and some knowledge of Oracle's internals.
This document is to be used only for testing purposes and should not be used in a production environment. The purpose is to show the audience how hackers can gain access to your system without knowing it - and how to prevent it.
This article provides several comparative methods to avoid primary key conflicts across multiple sites.
When you setup statspack with level 6 you can have information on the sql_plan associated with a sql.
I'm not really an "early-adopter" of technology. Don't get me wrong; I love it, I just don't want to feed the addiction. When I do get a new piece of technology though, it's like a fever; I can't concentrate on anything until I've read the manual from cover to cover and found out everything it can do, every built-in gizmo, and every trashy piece of after-market merchandise that can be plugged into it.
And I don't think I'm alone here. Working in I.T., there's no shortage of people who can peel off a half-hour litany on their new Blackberry/IPod/Notepad/Digital Watch within a day of purchase.
A handy alert log is invaluable for troubleshooting database problems. A RAC database has multiple alert logs.
I prefer to monitor them through a single table.
"A master failing to make an entry in the vessel's official
logbook as required by this part is liable to the Government for a
civil penalty of $200.
United States Code. Title 46 - Shipping. Subtitle II -Vessels and seamen, Part G - Merchant seamen protection and relief. Chapter 1113 -Official logbooks.
How meticulously do you keep your book log, Captain?
Luckily for us, our databases are as much ships as they are first mates. They are intelligent enough to keep their own records. And those logs are as important as vessel logs of the past, because the information carried by an early 21st century database could be easily worth more than 1450 tons of tea carried by Cutty Sark in 1870 en route from Shanghai to London.
As Oracle does all the mundane work, our role becomes more creative - to inspect and properly use the gathered information.
Today I have been experimenting with the new feature of continous mining with logmnr.
- Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
- ALTER DATABASE ADD SUPPLEMENTAL LOG DATA
or we don't see the funny things in the redologfiles
dbms_Logmnr.Start_Logmnr(StartTime => SYSDATE - 1 / 24, Options => dbms_Logmnr.dict_From_OnLine_Catalog + dbms_Logmnr.Continuous_Mine);