I’m excited about a new version of Oracle database 12c that will be released soon. In the last article I wrote about a considerable architectural change that Oracle is going to introduce with help of Oracle 12c Pluggable database feature. Let’s continue and explore some details of Oracle 12c Pluggable database feature.
Bear in mind that conventional database mode will be still available in 12c database. That means you will have two options of creating a usual old-fashioned Oracle database (non-CDB) or creating a Container Database (CDB) that will hold all your Pluggable Databases (PDB) that you will create or plug later. See below more details.
12c Pluggable Database details
– Each PDB has its own private data dictionary for customer-created database objects; CDB on the other hand as a whole has the data dictionary for the Oracle-supplied system each data dictionary defines its own namespace. In other words, there is global Data dictionary (CDB level) and local one (PDB level).
– There is a new split data dictionary architecture that allows a PDB to be quickly unplugged from one CDB and plugged into a different CDB
– Each PDB sees a read-only definition of the Oracle-supplied system
With a new Oracle 12c database release Oracle is going to come up in 2013 with a fundamentally new architecture called Pluggable Database that will greatly help enterprises in data and database consolidation as well in building a foundation for Private Database Clouds. Traditionally Oracle had several databases for several applications. Oracle 12c database will enhance its consolidation ability and will allow multiple customers data to coexist in a single database. Since 12c will be released pretty soon, I’d like to share some details on 12c Pluggable Database feature. Read more »
Issue / Oracle error
SQL*Plus: Release 10.2.0.5.0 - Production on Wed May 18 09:32:35 2011
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ORA-12547: TNS :lost contact when try to connect to Oracle.
I saw that TNS connection issue along with ORA-12547 Oracle error several times, usually when trying to connect to Oracle database server on Unix / Linux host with an OS user that does not belong to oinstall group (Oracle binaries owner group). In this case, interesting enough that local TNS connection to database (when using tnsnames alias) works fine: Read more »
I see a lot of questions on shared file systems that can be used when people move from single instance to Oracle RAC database and Grid Infrastructure. The most common question is the following: “Should I place archive logs in OCFS2 or ASM or ACFS of 11g?” I’ll try to clarify this topic below.
First we need to understand a separation between Oracle database files and non-database files. Read more »