Tag Archives: 12c

Playing with Oracle 12c and Virtual Box

I keep “playing’” with 12c, and this time I’d like to show you how easy is to install the Pre-Built VMs provided by Oracle.

As I mentioned, the process is very simple, these are the requirements to install it:

  • At least 2GB RAM. Default VM is 1G RAM, for better performance increase.
  • At least 15GB of free space (Note: virtualization works best with contiguous space so it is a good idea if on Windows to run a defrag program, and make sure you are using NTFS for your file system to handle large files on Windows. )
  • 2GHz Processor (a lesser processor will be acceptable but slower)
  • Mozilla Firefox 2.0 or higher, Internet Explorer 7 or higher, Safari 3.0 and higher or Google Chrome 1.0 or higher
  • Adobe Acrobat reader
  • Admin privileges on your box

So now that you know the minimum requirements, let’s move to the installation process:

  1. Download and install Oracle VM VirtualBox on your host system from HERE.
  2. Download the Virtual Machine from HERE. (DownloadOTN_Developer_Day_VM.ova (5,215,947,264 bytes, md5sum: 4e8ef75cdbd0fbe3d3beee8f873b2d4a)
  3. Open Oracle VM VirtualBox and Import your VM: File > Import Appliance to launch Appliance Import Wizard.
    Click Choose… to browse to the directory you re-assembled all the files in and select the OTN_Developer_Day_VM.ova.  Then click Next to begin importing the virtual machine. It will prompt you to agree to the appropriate developer licenses while importing. You will see ‘Oracle Developer Days (Powered Off)’ when it is finished importing.
  4. Test your VM: Once the import has completed, double-click the OTN Developer Days VM. Click OK to close the Virtualbox Information dialogs. When you get to the Enterprise Linux 6 screen you can now login. (Username and password is oracle.) Allow the process to complete; it is ready when you see a terminal window, which you can close.
  5. Once you are finished working in the guest VM you can shut it down via System > Shut Down; this will return the guest VM to the Powered Off state.

As you can see, the process is pretty simple right?

Have a nice day!!

12c, First Steps

After the Holidays, I was finally able to start with 12C!! So once I finish the installation, I tried to connect to the DB and create a user. That is when I discover that you need to connect to a special Database in order to perform that.

I got an error message creating a user.  Well, I figured out how to create a new user and a few other things.  I’m working with the DB12C database that comes with the install and all the parameters, etc. that come with it.

Evidently the default install comes with a PDB called PDBORCL.  So, I have two tns entries one for the parent CBD and one for the child PDB and they look like this:

DB12C =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)
(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = DB12C)
    )
  )

PDB =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)
(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = pdborcl)
    )
  )

So, if I connect as SYSTEM/password@DB12C I’m connected to the CDB and if I connect to SYSTEM/password@pdb I’m connected to the PDB.  When I connected to the PDB I could create a new user without getting an error.

But, when I first tried connecting to the PDB I got this error, even though the database was up:

ORA-01033: ORACLE initialization or shutdown in progress

So, to bring the database up (by the way, I’m on 64 bit Linux) after booting the Linux VM the following steps were required:

lsnrctl start
sqlplus / as sysdba
startup
alter session set container=PDBORCL;
startup

Interestingly there is only one pmon:

$ ps -ef | grep pmon
oracle   11865     1  0 09:12 ?        00:13:46 ora_pmon_DB12C

But you get different results when you query dba_data_files depending on whether connected to the CDB or PDB:

DB12C

FILE_NAME                                 
------------------------------------------
/u01/app/oracle/oradata/DB12C/system01.dbf 
/u01/app/oracle/oradata/DB12c/sysaux01.dbf 
/u01/app/oracle/oradata/DB12C/undotbs01.dbf
/u01/app/oracle/oradata/DB12C/users01.dbf

PDB

FILE_NAME                                                     
--------------------------------------------------------------
/u01/app/oracle/oradata/DB12C/pdborcl/system01.dbf             
/u01/app/oracle/oradata/DB12C/pdborcl/sysaux01.dbf             
/u01/app/oracle/oradata/DB12C/pdborcl/SAMPLE_SCHEMA_users01.dbf
/u01/app/oracle/oradata/DB12C/pdborcl/example01.dbf
/u01/app/oracle/oradata/DB12C/pdborcl/dbfs01.dbf

So, I guess each PDB has its own SYSTEM and SYSAUX tablespaces?

Lastly when running my scripts to poke around I edited my sqlplus header script to report which container you are in.  It looks like this now:

set linesize 32000
set pagesize 1000
set long 2000000000
set longchunksize 1000
set head off;
set verify off;
set termout off;

column u new_value us noprint;
column n new_value ns noprint;
column c new_value cs noprint;

select name n from v$database;
select user u from dual;
SELECT SYS_CONTEXT('USERENV', 'CON_NAME') c FROM DUAL;

set sqlprompt &ns:&cs:&us>

set head on
set echo on
set termout on
set trimspool on

It puts out a prompt like this:

CDB

DB12C:CDB$ROOT:SYSTEM>

PDB

DB12C:CDB$ROOT:SYSTEM>

 

Select Clause in 12c

Prior to Oracle12c you needed to use an inner query to get the 10 first rows of a table. Example:

Get the 10 first rows ordered by user_id in ascending order:

drop table DEMO1;

create table DEMO1 as select substr(username,1,20) username, user_id, from all_users;

select * from 
(select username, user_id from DEMO1 order by user_id asc)
where rownum <= 10;

USERNAME             USER_ID
-------------------- ----------
XS$NULL              2147483638
SYSKM                2147483619
SYSDG                2147483618
SYSBACKUP            2147483617
DVSYS                   1279990
DBFS_USER                   111
SCOTT                       109
BI                          108
SH                          107
IX                          106

 

Now with 12c, this is extremely simple!!!
Oracle 12c provides enhanced support for top-n analysis.

  • OFFSET provides a way to skip the N first rows in a result set before starting to return any rows
  • The FETCH clause limits the number of rows returned in the result set
  • For the result offset clause, the value of the integer literal must be equal to 0 (default if the clause is not given), or positive. If it is larger than the number of rows in the underlying result set, no rows are returned.
  • For the fetch first clause, the value of the literal must be 1 or higher. The literal can be omitted, in which case it defaults to 1. If the clause is omitted entirely, all rows (or those rows remaining if a result offset clause is also given) will be returned.

Here are several examples:

Select the First 3 rows:
select USER_ID, USERNAME from DEMO1 order by USER_ID FETCH FIRST 3 ROWS ONLY;
USER_ID    USERNAME
---------- ------------
 0         SYS
 7         AUDSYS
 8         SYSTEM
Select 3 rows after the first 4:
select USER_ID, USERNAME from DEMO1 order by USER_ID OFFSET 4 ROWS FETCH NEXT 3 ROWS ONLY;
USER_ID    USERNAME
---------- ------------
21         GSMADMIN_INTERNAL
22         GSMUSER
23         DIP
Select all the rows after the 5th one
select USER_ID, USERNAME from DEMO1 order by USER_ID OFFSET 5 rows ;
 USER_ID   USERNAME
---------- --------------------
 22        GSMUSER
 23        DIP
 36        ORACLE_OCM
 47        DBSNMP
 48        APPQOSSYS
 49        XDB
 50        ANONYMOUS
 60        GSMCATUSER
......
......
Select 31% of the rows:
select USER_ID, USERNAME from DEMO1 order by USER_ID FETCH FIRST 31 PERCENT ROWS ONLY;
USER_ID    USERNAME
---------- --------------------
 0         SYS
 7         AUDSYS
 8         SYSTEM
 13        OUTLN
 21        GSMADMIN_INTERNAL
 22        GSMUSER
 23        DIP
 36        ORACLE_OCM
 47        DBSNMP
 48        APPQOSSYS
 49        XDB
 50        ANONYMOUS
 60        GSMCATUSER
 61        WMSYS