Question:- Explain database white box testing and black box testing.
Answer:- The white box testing method mainly deals with the internal structure of a particular database, where users hide specification details. The white box testing method involves the following: • As the coding error can be detected by testing the white box, it can eliminate internal errors. • To check for the consistency of the database, it selects the default table values. • This method verifies the referential integrity rule. • It helps perform the module testing of database functions, triggers, views, and SQL queries. The black box testing method generally involves interface testing, followed by database integration. The black box testing method involves the following: • Mapping details • Verification of incoming data • Verification of outgoing data from the other query functions
Question:- How can you create empty tables with the same structure as another table?
Answer:- This can be achieved by fetching the records of one table into a new table using the INTO operator while fixing a WHERE clause to be false for all records. In this way, SQL prepares the new table with a duplicate structure to accept the fetched records. However, there are no records that will get fetched due to the WHERE clause in action. Therefore, nothing is inserted into the new table, thus creating an empty table. SELECT * INTO Students_copy FROM Students WHERE 1 = 2;
Question:- What is Oracle?
Answer:- Oracle is a company. Oracle is also a database server, which manages data in a very structured way. It allows users to store and retrieve related data in a multi-user environment so that the users can concurrently access the same data. All this is accomplished while delivering high performance. A database server also prevents unauthorized access and provides efficient solutions for failure recovery. A standby database is a database replica created by taking a backup of a primary database.
Question:- What is an Oracle index?
Answer:- An index is an optional structure associated with a table to have direct access to rows that can be created to increase the performance of data retrieval. An index can be created on one or more columns of a table.
Question:- Why is the index used?
Answer:- Indexes are used for the easy access of data. To increase the performance of retrieval data, Indexes are used. It helps to find the required data quickly without actually searching each row.
Question:- Who is responsible to update the indexes?
Answer:- Oracle is capable of maintaining and using indexes and Oracle automatically distributes the data into relevant indexes when any change is made in the table data.
Question:- What are the various databases available in the market?
Answer:- There are many databases available in the market. The commonly used databases are Oracle, IBM db2, Microsoft SQL Server, Microsoft Access, MySQL and SQLite, PostgreSQL, MariaDB.
Question:- There are many databases available in the market. The commonly used databases are Oracle, IBM db2, Microsoft SQL Server, Microsoft Access, MySQL and SQLite, PostgreSQL, MariaDB.
Answer:- Below 5 are the physical components of Oracle Database: Data files Control files Redo log files Password files Parameter files
Question:- What are the roles of DBA?
Answer:- A DBA has the authority to create new users, remove the existing users, or modify any of the environment variables or privileges assigned to other users. • Manage database storage • Administer users and security • Manage schema objects • Monitor and manage database performance • Perform backup and recovery • Schedule and automate jobs
Question:- What are the different Oracle Database objects?
Answer:- Tables Views Indexes Synonyms Sequences Tablespaces
Question:- What is a Synonym in Oracle terminology?
Answer:- A synonym which is also known as an alias is an identifier that can be used to reference another database object in a SQL statement. A table, view, sequence are the types of database objects that can be created for a synonym.
Question:- Explain the types of Synonyms?
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.
Question:- What are the types of backups in Oracle?
Answer:- The main four types of backups in Oracle are: (ⅰ) COLD Backup (ⅱ) HOT Backup (ⅲ) Import – Export Backup (ⅳ) RMAN Backup
Question:- What are Hot Backup and Cold 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.
