Oracle Database parameter MAX_STRING_SIZE controls the maximum size of VARCHAR2, NVARCHAR2, and RAW data types in SQL. From Oracle Database 12c onwards, table column(s) length can be modified to greater than 4000 characters when this parameter value is set to EXTENDED. Allowed values for this parameter are: STANDARD: Default value. Means that the length limits […]
Oracle 18c
Connecting PDB in Oracle 12c and 19c
To connect as sys or other elevated local users, use the same methods as below, but use ‘as sysdba’ wherever necessary. Method 1 alter session set container = pdbName; Method 2 For other methods, you need to know the service-name for the PDB: – Get the service name for the PDB: SELECT name || ‘ […]
Establish Connection in CDB and PDB
When it comes to Multi-tenant architecture, one question that comes to our mind is how to connect to container database and pluggable database. Today we will see all possible ways to connect to the container database. Obviously, we connect database using service name for the non-local connection. When we create CDB, a service is created […]
How to Use Startup, Shutdown, and Alter Database commands in Oracle 12c
Before 12c there are only a few commands available for startup and shutdown but if we follow that we end up starting and stopping only cdb. The commands in 12c to start and shutdown the CDB and PDB are a little different than the previous version. Below list of commands were used in earlier versions […]
How to get datafile information when PDB is Mounted/Read-Write/Restricted Mode
Question: How to get PDB Datafile information when PDB in different Mode? Case 1 – PDB in mounted Mode PDB Status: SQL> select pdb_id, pdb_name, con_uid,status from dba_pdbs; PDB_ID PDB_NAME CON_UID STATUS ———- ————– ———- ————- 3 [PDB12C] 515133920 NORMAL 2 PDB$SEED 4105546291 NORMAL SQL> select con_id, name, open_mode, restricted from v$pdbs; CON_ID NAME OPEN_MODE […]
Oracle Multitenant: How to Create CDB and PDB
Creating a CDB The steps required to create a new CDB, using either DBCA or SQL*Plus, are the same. The first step, as for any database, non-CDB or CDB, consists of configuring an instance with an init.ora parameter file and then starting the instance. The second step is the creation of the CDB using the […]
Beginners Guide to Oracle Database 18c Multitenant Architecture
Challenges Starting with Oracle Database 12c, the multitenant architecture enables you to have many pluggable databases inside a single Oracle Database instance. What is the benefit of using the multitenant architecture in Oracle Database 18c? Currently, many Oracle customers have large numbers of “departmental” applications built on Oracle RDBMS. These applications rarely use a significant […]