In previous article we have seen various methods of connecting to and starting and shutting down pluggable databases. This article focuses on steps to unplug the database from container database and then plugging it back to same or another container. Here I have demonstrated the method using command prompt, whereas you can also manage the plugging and unplugging through Database Configuration Assistance (DBCA).
Before unplugging database make sure you are connected to appropriate database and close the pluggable database.
Here, it is important to understand that when we unplug the database, some repository needs to crated that will provide the metadata about the database when we wish to plug the same database back to container database. The statement you see in following screen shot to unplug the database generates xml file. This xml file stores the information about name, full paths of tablespaces and datafiles.
In our scenario, we are plugging back the unplugged database to the same container database. But in case where you need to unplugged database to another container database, it is always essential to verify the compatibility of pluggable database with container database. The verification can be done with Oracle Package and Stored Procedure.
”DB_PDB.CHECK_PLUG_COMPATIBILITY”. This can be simply verified using PL/SQL code written below:
As we seen, the output results that unplugged database is compatible we can proceed further plugging it. Here the xml file will be used generated while unplugging database, for creation and plugging the database.
Once pluggable database is created and plugged, you can see that newly created database is in mount state.
Shift to pluggable database and open it.
Here we are done with unplugging and plugging databases. To see the logs of complete process from unplugging database to plugging it back again, you can refer to alert log file. This will help you clearly understand the internals of plugging and unplugging databases.
That’s all with basics of multi-tenant database, we have seen so far with the series of articles from introduction to this point. Next we shall go through the multi-tenant database with Oracle other technologies like Data Guard.
In previous article we saw the process for creating Container and Pluggable Databases using Database Configuration Assistance (DBCA). There are difference in connecting to pluggable database as compared to those of container database and databases in previous releases. Also the way we need startup and shutdown the pluggable database.
It is really surprising and interesting to know, when we start the container database, all the pluggable database within are automatically mounted. There is no special mechanism to start pluggable database when we start the container database. We can manage the pluggable database in two ways:
Connecting to Container Database
We created the container database named CBD.
To check the services under container database, and information of which pluggable database it holds, you can use the dictionary view V$SERVICES
To get the details of all the services, you can use “lsnrctl” utility
You can get the details of current container with 2 methods as show:
You can switch to container inside container simply with “Alter Session Set” Command as:
Connecting to pluggable database
You can connect to pluggable database using “tnsname” or direct connect using service name. Connect to database and make sure that you are connected to appropriate database as:
Start up and Shut Down Pluggable database.
Startup and Shutdown process is simple as that of databases of previous releases. There is difference in managing pluggable database. When connected to container database, you can use “Alter Pluggable database” statements to manage the database. Some examples of the same are given below.
Following are possible options to perform startup operations on pluggable database:
ALTER PLUGGABLE DATABASE <pdb_name>OPEN READ WRITE [RESTRICTED] [FORCE];
ALTER PLUGGABLE DATABASE <pdb_name> OPEN READ ONLY [RESTRICTED] [FORCE];
ALTER PLUGGABLE DATABASE <pdb_name> OPEN UPGRADE [RESTRICTED];
ALTER PLUGGABLE DATABASE <pdb_name> CLOSE [IMMEDIATE];
If you have multiple pluggable database, “Alter Pluggable Database” can be used manage one or more database with single command. You need to specify the names of pluggable database as below:
ALTER PLUGGABLE DATABASE <pdb_1_name>,<pdb_2_name> [OPEN]/[CLOSE];
In case your container has few pluggable database and you wish to keep some of them shutdown and start rest you can use “Alter Pluggable database…EXPECT” command, as:
ALTER PLUGGABLE DATABASE ALL EXPECT pdb OPEN;
As said earlier that there is no special mechanism to start pluggable database when we start the container database, but we can achieve that creating the trigger on container database when starts to perform the startup of the pluggable databases automatically within it.
CREATE OR REPLACE TRIGGER openallpluggabledatabases
AFTER STARTUP ON DATABASE
EXECUTE IMMEDIATE ‘ALTER PLUGGABLE DATABASE ALL OPEN’;
This was all about connecting and managing startup/shutdown of pluggable databases. In coming article we shall understand how to view the information/properties of container and pluggable database using data dictionary view or SQL*Plus.
Backup Services are considered as one of the most important services which is very essential now a days. Local backup is always considered to be an easy task the physical media where you are storing the backups, like the DVDs or external disk, may not be very reliable in the long term. The other disadvantage is that local backups don’t always happen in real-time.
Online backup is the perfect solution to many of the business almost to all businesses. These services are cheap and affordable to as it is a secured way to protect one’s data. It is therefore recommended that one must switch to an online backup service – these are inexpensive and will automatically copy one’s computer’s data over the Internet to a more secure off-site location (aka the data center) in near real-time without anyone’s involvement.
Now-a-days all the crucial information one generally stores in the computers. Whether it’s photos and music or business documents and financial records, everything is digital. Digital data is rapidly growing at a rate of 80% each year, and businesses are responsible for maintaining 85% of that information. Data Loss can happen any time any moment in the current time span. There can be different reasons to this like, hard drive crashes, spilled drinks, and accidental file deletion can occur at any time and put your company’s future in jeopardy. In fact, 93% of all companies that suffer significant data loss close down within 5 years!
Traditional backup services can be tedious and time consuming too. These backup solutions can take weeks to implement, leaving your business vulnerable to revenue and productivity loss. Traditional outsourcing models expect you to give out your entire IT infrastructure workload leaving you with no control and conversely, more cause for worry. And very-long-term contracts tend to leave you locked into an outdated business plan. Many backup services offer a limited free plan, often for personal use. Often it is possible to increase the free backup limit through coupons, referrals, or other means that are not included in this column. This column also does not include free trials that are only available for a limited period of time.
The process which involves the backing up of mission critical data is often known as the backup services. Backup is the basic process to protect your data from any harmful effects while duplicating it and restoring after the processing of the applications. The basic purpose of backing up the data is that, Data is generally regarded as a company’s first or second most valuable asset — right on par with people. Equally important with backing up data is the ability to recover that same data and recover it in a timely fashion to keep your business up and running.
In today’s era of IT, its must that every services should be supported by the backup and recovery services as it provides the security and stability of the business enterprises. The most important backup and recovery process involves, such as data backup service security, data backup testing, data deduplication technology and more.
The basic need involves the function of safeguarding the data for the purpose of maintaining the high resource availability. The responsibility of a backup service provider includes many a critical aspects, being in charge of data backup and recovery usually means you’re in charge of two things: backup operations and backup administrations. Daily tasks such as making sure backups completed, ejecting tapes from a library and inserting scratch tapes have traditionally been the responsibilities of backup operators.
There are many similar terms or the activities involved while opting a backup and recovery process, many storage and backup administers often confuse data backup with data archiving. But the two are separate functions and should be treated as such. There are also different types of backup systems involved, like the most common backup types are a full backup, incremental backup and differential backup. Other backup types include synthetic full backups, mirroring, reverse incremental and continuous data protection (CDP).
The backup and recovery systems needs to be maintained regularly in order not to keep the business running. Testing is one of the major criteria to be considered while one is on backup and recovery process. Testing is often the missing link in making backups. Too many companies spend a lot of time backing up their data only to find the backups won’t work when something goes wrong with their data storage.
With the above explanations we can say that the backup and recovery process holds a great importance in the IT world as to have the data secured as well to keep the business running effectively.