Hi to all.
I found a nice series of articles for beginners. I highly suggest to review them if you are new to Oracle:
Hi to all.
I found a nice series of articles for beginners. I highly suggest to review them if you are new to Oracle:
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:
So now that you know the minimum requirements, let’s move to the installation process:
As you can see, the process is pretty simple right?
Have a nice day!!
I found a VERY interesting link at Oracle’s website showing a lot of information on 12c:
http://www.oracle.com/webfolder/technetwork/tutorials/obe/db/12c/r1/poster/OUTPUT_poster/poster.html
It contains information on:
Enjoy!!!
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:
The ADR Command Interpreter (ADRCI) is a command-line tool that you use to manage Oracle Database diagnostic data and is part of the fault diagnosability infrastructure introduced in Oracle 11g. ADRCI enables you to:
Diagnostic data includes incident and problem descriptions, trace files, dumps, health monitor reports, alert log entries, and more.
ADRCI has a rich command set, and can be used in interactive mode or within scripts. In addition, ADRCI can execute scripts of ADRCI commands in the same way that SQL*Plus executes scripts of SQL and PL/SQL commands.
Invoke ADRCI as the Oracle OS user:
> adrciADRCI: Release 11.2.0.3.0 - Production on Fri Jan 17 22:38:57 2014 Copyright (c) 1982, 2011, Oracle and/or its affiliates. All rights reserved. ADR base = "/opt/oracle"adrci> show homeADR Homes: diag/diagtool/user_oracle/host_12454656_11 diag/rdbms/orcl/ORCL diag/asm/+asm/+ASM1 diag/tnslsnr/orcl/listener_cadSet the home adrci> set home diag/rdbms/orcl/ORCL
To check the alert log use the following option.
adrci> show alert -tail -f
2014-01-21 10:20:23.418000 -05:00
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
Thread 1 closed at log sequence 1176
Successful close of redo thread 1
Completed: alter database close normal
alter database dismount
Completed: alter database dismount
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
2014-01-21 10:20:24.852000 -05:00
ARCH: Archival disabled due to shutdown: 1089
Shutting down archive processes
Archiving is disabled
Archive process shutdown avoided: 0 active
Stopping background process VKTM:
2014-01-21 10:20:27.036000 -05:00
Instance shutdown complete
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.
AWR is the best tool available to identify performance issues on your database. It has several tools to help you identify performance issues and all the information is displayed in a single HTML page. AWR periodically gathers and stores system activity and workload data which is then analyzed by ADDM.
Every layer of Oracle is equipped with instrumentation that gathers information on workload which will then be used to make self-managing decisions. AWR is the place where this data is stored. AWR looks periodically at the system performance (by default every 60 minutes) and stores the information found (by default up to 7 days). AWR runs by default and Oracle states that it does not add a noticeable level of overhead. A new background server process (MMON) takes snapshots of the in-memory database statistics (much like STATSPACK) and stores this information in the repository.
For more details on its usage, please ckick HERE
Nice Multitenant Architecture Diagram from Oracle’s website
I found the following Database Architecture Diagram for Oracle Database 12c on Oracle’s website. It lists all the processes and the relationship between processes and other database components.

And below is a YouTube link which gives database architecture overview.
Oracle Database 12c Architecture Overview