→ Here we can see that new pluggable database PDB1 created from another pluggable database DEV even if the PDB$SEED is in mount state. Here we can see from where the PDB is created Drop undo tablespace in PDB
Data Consistency In Oracle Database, each user must see a consistent view of the data, including visible changes made by a user’s own transactions and committed transactions of other users. For example, the database must prevent the dirty read problem, which occurs when one transaction sees uncommitted changes made by another concurrent transaction. Oracle Database … Read more
Structured Query Language (SQL) is the set of statements with which all programs and usersaccess data in an Oracle Database. Application programs and Oracle tools often allow usersaccess to the database without using SQL directly, but these applications in turn must useSQL when executing the user’s request. SQL is a set-based declarative language that provides … Read more
In Oracle Database, a database schema is a collection of logical data structures, or schema objects. A database user owns a database schema, which has the same name as the user name. Schema objects are user-created structures that directly refer to the data in the database. The database supports many types of schema objects, the … Read more
Overview of Data Files At the operating system level, Oracle Database stores database data in structures called data files. Every Oracle database must have at least one data file. Use of Data Files Oracle Database physically stores tablespace data in data files. Each nonpartitioned schema object and each partition of an object is stored in … Read more
PARAMETER & PASSWORDFILE: * Create pfile from spfile to location ‘/home/oracle/init<sid.ora>’ * Create password file with sys password as oracle1 * Create parameterfile in different location /u01 & start the DB to up and running condition. * How to check all parameters associated with database? * How to change specific parameters with Scope=both/spfile/memory? * How … Read more
A system change number (SCN) is a logical, internal time stamp used by Oracle Database. SCNs order events that occur within the database, which is necessary to satisfy the ACID properties of a transaction. Oracle Database uses SCNs to mark the SCN before which all changes are known to be on disk so that recovery … Read more
Below are the list of additional privileged user in 12c apart from the privileged user SYSOPER, SYSDBA, SYSASM. SYSBACKUP : It will be used to perform all backup and recovery related operations either via RMAN or SQL*PLUS. SYSDG : It is in place to separate the Data Guard related operations from other activities. SYSKM : It will be responsible for all TDE (Transparent Data … Read more
Useful views to get index details: dba_indexes dba_segments dba_ind_columns dba_ind_partitions user_indexes user_segments user_ind_columns user_ind_partitions Query to check Index on a Table in Oracle. Find the list of top index size corresponding to a table. Check Index Column on a Table in Oracle. Find total index size of respective tables in a schema. Find the list … Read more
In a typical use case, you manually shut down the database, making it unavailable for users while you perform maintenance or other administrative tasks. You can use the SQL*Plus SHUTDOWN command or Enterprise Manager to perform these steps. Phase Mount Stage Description 1 Database closed The database is mounted, but online data files and redo … Read more