Tag: memory

Oracle Database Application Security Book

Posted on by Osama Mustafa in News

Finally …

The Book is alive

For the first time the book which is dicussed critcal security issues such as database threats, and how to void them, the book also include advance topics about Oracle internet directory, Oracle access manager and how to implement full cycle single sign on,

Focus on the security aspects of designing, building, and maintaining a secure Oracle Database application. Starting with data encryption, you will learn to work with transparent data, back-up, and networks. You will then go through the key principles of audits, where you will get to know more about identity preservation, policies and fine-grained audits. Moving on to virtual private databases, you’ll set up and configure a VPD to work in concert with other security features in Oracle, followed by tips on managing configuration drift, profiles, and default users.

What You Will Learn:- 

  • Work with Oracle Internet Directory using the command-line and the console.
  • Integrate Oracle Access Manager with different applications.
  • Work with the Oracle Identity Manager console and connectors, while creating your own custom one.
  • Troubleshooting issues with OID, OAM, and OID.
  • Dive deep into file system and network security concepts.
  • First time chapter that include most of the critical database threats in real life.

 

You can buy the book now from amazon here

 

Cheers

Osama

SGA_MAX_SIZE & SGA_TARGET / MEMORY_TARGET & MEMORY_MAX_TARGET

Posted on by Osama Mustafa in Database
In this article i will discuss the Difference between these parameter and how to use them ,  MEMORY_TARGET & MEMORY_MAX_TARGET  parameters appear in 11g .

I will depend on oracle documentation to describe these parameter :

SGA_MAX_SIZE sets the overall amount of memory the SGA can consume but is not dynamic.

The SGA_MAX_SIZE parameter is the max allowable size to resize the SGA Memory area parameters. If the SGA_TARGET is set to some value then the Automatic Shared Memory Management (ASMM) is enabled, the SGA_TARGET value can be adjusted up to the SGA_MAX_SIZE parameter, not more than SGA_MAX_SIZE parameter value.

MEMORY_TARGET & MEMORY_MAX_TARGET 

you can manage SGA and PGA together rather than managing them separately.

If you set SGA_TARGET, SGA_MAX_SIZE and PGA_AGGREGATE_TARGET to 0 and set MEMORY_TARGET (and optionally MEMORY_MAX_TARGET) to non zero value, Oracle will manage both SGA components and PGA together within the limit specified by you.

If MEMORY_TARGET is set to 1024MB, Oracle will manage SGA and PGA components within itself.

If MEMORY_TARGET is set to non zero value:

  • SGA_TARGET, SGA_MAX_SIZE and PGA_AGGREGATE_TARGET are set to 0, 60% of memory mentioned in MEMORY_TARGET is allocated to SGA and rest 40% is kept for PGA.
  • SGA_TARGET and PGA_AGGREGATE_TARGET are set to non-zero values, these values will be considered minimum values.
  • SGA_TARGET is set to non zero value and PGA_AGGREGATE_TARGET is not set. Still these values will be autotuned and PGA_AGGREGATE_TARGET will be initialized with value of (MEMORY_TARGET-SGA_TARGET).
  • PGA_AGGREGATE_TARGET is set and SGA_TARGET is not set. Still both parameters will be autotunes. SGA_TARGET will be initialized to a value of (MEMORY_TARGET-PGA_AGGREGATE_TARGET).

You can have some Description  On http://support.oracle.com

 Thank you
Osama Mustafa

Check memory On Linux

Posted on by Osama Mustafa in Operating system
Sometime you as DBA you need to check your memory On Operating System Level, i will give you some command will useful to you :

1-free -m / free -g

m : megabytes
g : gigabytes

              total    used     free   shared  buffers   cached 
 Mem:           503     451       52        0       14      293 
 -/+ buffers/cache:     143      360 
 Swap:         1027       0     1027

 another example :

free -t -m
       total       used       free     shared    buffers     cached
Mem:           750        625        125          0         35        335
-/+ buffers/cache:        253        496
Swap:          956          0        956
Total:        1707        625       1082
2-vmstat

procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy id wa
1  0      0 131620  35432 341496    0    0    42    82  737  1364 15  3 81  1
 
 
 
 
3-top 
 
 
 


4-gnome-system-monitor


 




 


 


The below Command for clear cache memory in linux 






sync; 


echo 3 > /proc/sys/vm/drop_caches




 you can make it as job in linux save in it crontab 






0 * * * * /root/clearcache.sh


 




Create a file in '/root' called 'clearcache.sh' with the following content:






#!/bin/sh  
 sync; echo 3 > /proc/sys/vm/drop_caches




 


  


Thank you 


osama mustafa 



	

	

	




	
	

		
tns-12560 message 12560 not found
				

					Posted on  by Osama Mustafa in Database				


				

	

		
Sometimes Users Cannot access to Database You Need To check The following :


Sqlplus / as sysdba


Show parameter local_listener ;


You have to see output like this :





local_listener            (DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=you-ip-address)(PORT=1521))))


  If you see Null Value Do the Following :




Alter system set local_listener=’(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.250.25)(PORT=1521))))‘ scope=memory ;


Or For Real Application :


Alter system set local_listener=’(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.250.25)(PORT=1521))))‘ scope=memory sid=’you-node-name’;


Scope = memory For Test Purpose


Sql > Alter system register ;


Now You should see database name service on listener ;


to Apply these Changes all we have to do is scope=spfile like the following :




   Alter system set local_listener=’(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.250.25)(PORT=1521))))‘ scope=spfile ; 


Or For Real Application :


   Alter system set local_listener=’(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=172.16.250.25)(PORT=1521))))‘ scope=spfile sid=’you-node-name’; 


Thank you
Osama Mustafa