Sunday again, it is the exiting Oracle class that takes me one whole day.
What's there?
1) Oracle memory structure
2) Oracle EM
3) About the error Ora-01031: Insufficient Privileges
The course today is mainly talking about the element field of the oracle instance. Then in order to shows us the more concrete memory consumption of an oracle instance, Ken showed us the Oracle enterprise management panel. After that, he came back to chapter 2,3,4 of the textbook which is about installing Oracle database instance. Since we have already gone through the installation in the previous two weeks, it should not be a big problem, however, when I switch on the instance that was built in the pre-installed database software based on RAC. I could not startup the database---due to error Ora-01031: Insufficient Privileges. I have been searching for solution against this problem and find several solution. However, this solution cannot be verified now, so I would better put it down here for my own reference next week.
1) Oracle instance can be a complicated one, it contain two main part: SGA(physically RAM) and processes.
Here lets recall how what is an instance: an instance is serial of instruction that enable user to operate a database. Without an instance, a database, simply speaking, is a group of data that you cannot make use of.
So instance is the tool you can move the data between disk and SGA, and manipulate it into something meaningful and useful by those instance process. A more accurate and official definition is:
An instance is a set of memory structures that manage database files. The instance consists of a shared memory area, called the system global area (SGA), and a set of background processes.
SGA contains a lot of share pool, database buffer cache, redo log buffer, and other small area like stream cache. Database buffer cache usually take up 2/3 of the RAM given to an instance, because it is the area to store the data taken from the disk. The data from the actually database should first be moved here for user's usage. Therefore, it should be big enough to store the data, in order to lessen the read/write of the hard disk.
The data updated by the user will be kept in the database buffer cache until a certain time, then all the changed data(called dirty block) will be written to the disk as a permanently modification on the data. This predefined time should not be too short in order to maintain database efficiency. The reliability of the modification of data lies on the other area: redo log buffer.
The redo log buffer takes up a rather small area in SGA, in most of the time, the log stored here will be recorded into the disk in a very short time.
This mechanism enable the reliability of the database operation---most the misdo should be able to be recovered by the redo log---at the same time ensure the efficiency of database operation. Most of the read operation is implemented between database buffer cache and disk, while most of the write operation is implemented between redo log cache and disk. It lessen the time for collision operation in read and writing data.
2) Oracle Enterprise Manager
All the above are sentence on the book, how about an example? This can be shown in the Oracle Enterprise Manager. Oracle EM is a web-based control panel of an instance which turns out to be a very power tool for a dba. In the Oracle EM, you can check the status of an instance, and schedule jobs on the instance.
How to turn on the EM? You can easily gain access of the EM by entering a line of script into the terminal:
emctl start dbconsole The terminal will return a URL that can direct you to the EM.
Open the webpage, login using "sys" and sysdba password with "SYSDBA" as operator, then you can access to the EM panel.
But I have failed to login, it keeped return to me that cannot login. I tried many combination of acc and password, but still failed! Then I realize that my instance is not started up yet. So I started up the database:
sqlplus sys/oracle as sysdba
SQL>startup.
SQL> database mounted.
Tried login the EM as sys again, success!
3) About the error Ora-01031: Insufficient Privileges
The error returned in when I tried to startup an instance that was installed in the database software on the Oracle Cluster. The error, I assume, is caused by some wrong setting during the installation since I was quite confused when I installed the database software on the cluster, and might mess up some parameter setting.
The script goes like:
lsnrctl start;
sqlplus sys/oracle as sysdba
SQL> startup;
SQL> Ora-01031: Insufficient Privileges
So, it is telling that the user "oracle" has no privilege to startup a database.
Have a preliminary search for the reason, it could be because the oracle is not inside the group "dba".
To verify this, I went to the system>user and privilege panel, and fond that the user group indeed is different from a workable database setting, or more accurately, it is an OS setting.
In the OS with error, there are only two groups: dba, oinstall, while the oinstall is the primary group of the user "oracle". But the other one are configured with four groups: dba, oinstall, sysadmin, sysopera.
I have found many solution on the internet solving the problem, yet the following two post should be the most explanatory ones:
1. http://www.dba-oracle.com/t_ora_01031.htm
2. http://askdba.org/weblog/2008/05/ora-1031-as-sysdba/
Need to verify next Sunday.
There was an opportunity in front of me today, but I could not catch it, because I am not competent-- I get to reconsider what I can do to catch and attract opportunities to me.
Opportunities, though can be attracted by your ambition and appearance, can only be caught by the value to can create.
2013/11/10
What's there?
1) Oracle memory structure
2) Oracle EM
3) About the error Ora-01031: Insufficient Privileges
The course today is mainly talking about the element field of the oracle instance. Then in order to shows us the more concrete memory consumption of an oracle instance, Ken showed us the Oracle enterprise management panel. After that, he came back to chapter 2,3,4 of the textbook which is about installing Oracle database instance. Since we have already gone through the installation in the previous two weeks, it should not be a big problem, however, when I switch on the instance that was built in the pre-installed database software based on RAC. I could not startup the database---due to error Ora-01031: Insufficient Privileges. I have been searching for solution against this problem and find several solution. However, this solution cannot be verified now, so I would better put it down here for my own reference next week.
1) Oracle instance can be a complicated one, it contain two main part: SGA(physically RAM) and processes.
Here lets recall how what is an instance: an instance is serial of instruction that enable user to operate a database. Without an instance, a database, simply speaking, is a group of data that you cannot make use of.
So instance is the tool you can move the data between disk and SGA, and manipulate it into something meaningful and useful by those instance process. A more accurate and official definition is:
An instance is a set of memory structures that manage database files. The instance consists of a shared memory area, called the system global area (SGA), and a set of background processes.
SGA contains a lot of share pool, database buffer cache, redo log buffer, and other small area like stream cache. Database buffer cache usually take up 2/3 of the RAM given to an instance, because it is the area to store the data taken from the disk. The data from the actually database should first be moved here for user's usage. Therefore, it should be big enough to store the data, in order to lessen the read/write of the hard disk.
The data updated by the user will be kept in the database buffer cache until a certain time, then all the changed data(called dirty block) will be written to the disk as a permanently modification on the data. This predefined time should not be too short in order to maintain database efficiency. The reliability of the modification of data lies on the other area: redo log buffer.
The redo log buffer takes up a rather small area in SGA, in most of the time, the log stored here will be recorded into the disk in a very short time.
This mechanism enable the reliability of the database operation---most the misdo should be able to be recovered by the redo log---at the same time ensure the efficiency of database operation. Most of the read operation is implemented between database buffer cache and disk, while most of the write operation is implemented between redo log cache and disk. It lessen the time for collision operation in read and writing data.
2) Oracle Enterprise Manager
All the above are sentence on the book, how about an example? This can be shown in the Oracle Enterprise Manager. Oracle EM is a web-based control panel of an instance which turns out to be a very power tool for a dba. In the Oracle EM, you can check the status of an instance, and schedule jobs on the instance.
How to turn on the EM? You can easily gain access of the EM by entering a line of script into the terminal:
emctl start dbconsole The terminal will return a URL that can direct you to the EM.
Open the webpage, login using "sys" and sysdba password with "SYSDBA" as operator, then you can access to the EM panel.
But I have failed to login, it keeped return to me that cannot login. I tried many combination of acc and password, but still failed! Then I realize that my instance is not started up yet. So I started up the database:
sqlplus sys/oracle as sysdba
SQL>startup.
SQL> database mounted.
Tried login the EM as sys again, success!
3) About the error Ora-01031: Insufficient Privileges
The error returned in when I tried to startup an instance that was installed in the database software on the Oracle Cluster. The error, I assume, is caused by some wrong setting during the installation since I was quite confused when I installed the database software on the cluster, and might mess up some parameter setting.
The script goes like:
lsnrctl start;
sqlplus sys/oracle as sysdba
SQL> startup;
SQL> Ora-01031: Insufficient Privileges
So, it is telling that the user "oracle" has no privilege to startup a database.
Have a preliminary search for the reason, it could be because the oracle is not inside the group "dba".
To verify this, I went to the system>user and privilege panel, and fond that the user group indeed is different from a workable database setting, or more accurately, it is an OS setting.
In the OS with error, there are only two groups: dba, oinstall, while the oinstall is the primary group of the user "oracle". But the other one are configured with four groups: dba, oinstall, sysadmin, sysopera.
I have found many solution on the internet solving the problem, yet the following two post should be the most explanatory ones:
1. http://www.dba-oracle.com/t_ora_01031.htm
2. http://askdba.org/weblog/2008/05/ora-1031-as-sysdba/
Need to verify next Sunday.
There was an opportunity in front of me today, but I could not catch it, because I am not competent-- I get to reconsider what I can do to catch and attract opportunities to me.
Opportunities, though can be attracted by your ambition and appearance, can only be caught by the value to can create.
2013/11/10
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