Answer:- There are two types of Synonyms which are- Public and Private. A public synonym isn’t part of any schema. A public synonym is one that can be used by any database user. A private synonym does belong to a specific schema. In other words, when only the owner can access it, it is called a private synonym.

Answer:- The main four types of backups in Oracle are: (ⅰ) COLD Backup (ⅱ) HOT Backup (ⅲ) Import – Export Backup (ⅳ) RMAN Backup

Answer:- Hot backup is also recognized as an Online Backup because here the backup is taken while the database is active and running. And when the backup can only happen while the database is in shut down mode then it is called Cold Backup which can also be identified as Offline Backup.

Answer:- Database users’ passwords are stored in the database’s data dictionary. When a user attempts to log into the database, the user’s usernames and passwords are compared to the values contained in the database. The user is given database access only if the username and password match. The data dictionary is stored in the database and can be accessed as long as the database is available. The dictionary also contains the passwords for the administrators. The data dictionary would be unavailable until the database is locked. Since starting up a down database is one of the administrator’s jobs, there needs to be a way for them to log in even if the database is locked. That’s where the password file comes into the picture. A password file is an operating system file that is held on a separate disc from the database. It stores the username and password for users with the SYSDBA or SYSOPER privileges. And when the database is down, administrators with certain privileges are authenticated using the password files.

Answer:- All the tables are stored in data files. The data file has all the data stored. The data files hold all the database data. The data of relational database structures, such as tables and indexes, is bodily stored in the data files owed for a database

Answer:- To switch from an init.ora file to a spfile, we should create spfile from pfile command then shutdown instance and startup once again

Answer:- The five type of SQL statements are: 1. Data Definition Language 2. Data Manipulation Language 3. Transactional control 4. Session Control 5. System Control

Answer:- The process of arranging data in a database is known as normalization. This involves building tables and defining relationships between them according to rules designed to protect data while also allowing the database to be more flexible by removing redundancy and conflicting dependencies.

Answer:- A binary file that records the physical structure of the database and is required to start and run the database. A control file contains information such as • Data file • Database name • Redo file name • Locations of associated data files and redo files. • Timestamp of database creation. • Current log sequence number • Checkpoint information

Answer:- Steps to recover a lost control file are: 1. Start the database in the NOMOUNT mode 2. Create the control file from the control file backup with CREATE CONTROLFILE statement, and place it in the correct location. 3. Mount the database 4. Recover the database 5. Open the database

Answer:- The redo log’s main purpose is to keep track of all data changes. If a failure stops personalised data from being permanently written to data files, corrections may be made from the redo log, ensuring that the work is never wasted.

Answer:- A parameter file is a text file that includes a list of initialization parameters as well as their values. Initialization parameters are defined in a parameter file that is exclusive to your installation.

Answer:- The recovery catalog is a database scheme that contains the metadata that RMAN manages for data restoration and recovery processes. The metadata used by RMAN for reinstallation and healing process is stored in a recovery catalog. The RMAN metadata is still present in the recovery catalogue even if the target control file and all backups are lost.

Answer:- When the database is created, the system tablespace is formed. Since this tablespace contains all of the data dictionary tables, it is used to create a number of database objects. For the database to run efficiently, the system tablespace must remain online.