Oracle Interview Questions – Part 45

Q.what is the physical database structure? A.Physical database structure The physical database structure comprises of datafiles, redo log files and control files 1.Datafiles Datafiles contain database’s data. The data of logical data structures such as tables and indexes is stored in datafiles of the database. One or more datafiles form a logical unit of database […]

Oracle Interview Questions – Part 44

Q.What is a shared pool?  A.It is the area in SGA that allows sharing of parsed SQL statements among concurrent users. Q.What is snapshot in oracle?  A.It is a read only copy of a table or a subset of a table.A recent copy of a table or a subset of rows or cols of a […]

Oracle Interview Questions – Part 43

Q.Explain different types of segment. Data segment, Index segment, Rollback segment and temporary segment. A.There are four types of segments used in Oracle databases: -data segments -index segments -rollback segments -temporary segments Data Segments: There is a single data segment to hold all the data of every non clustered table in an oracle database. This […]

Oracle Interview Questions – Part 42

Q.What is correlated sub-query?      A.In a simple SubQuery, the result retrieved by the inner query is fed to the outer query. The outer query takes the result as its input and processes it to produce its output.However, in a corelated sub query, a correlated sub-query is dependent upon the outer query.The outer query and the […]

Oracle Interview Questions – Part 41

Q.What Is a Dynamic Performance View in Oracle? A.Oracle contains a set of underlying views that are maintained by the database server and accessible to the database administrator user SYS. These views are called dynamic performance views because they are continuously updated while a database is open and in use, and their contents relate primarily […]

Oracle Interview Questions – Part 39

Q.What is a synonym ? Synonym, as the name suggests, is an alternative name for an object. It can be used for simplifying names that are lenghy or complex, for e.g you can use a simple synonym for accessing objects of other users, for which you had to prefix username to the object. Q.What is […]

Oracle Interview Questions – Part 40

Q.What is the difference between DATABASE ADMINISTRATION & ORACLE? A.Database Administration is task of managing the database. Oracle is RDBMS(Relational database management system),is a software used to create and manage the database. Basically used to: 1.Create database. 2.Store data in to the database. 3.Manipulate the already existing data in the database. 4.Retrieve the data from […]

Oracle Interview Questions – Part 37

Q.What is Row Migration and Row Chaining? Row Migration refers to rows that were moved to another blocks due to an update making them too large to fit into their original blocks. Oracle will leave a forwarding pointer in the original block so indexes will still be able to “find” the row. Note that Oracle […]

Oracle Interview Questions – Part 36

Q.Can you assign Priority to users? YES. This is achievable with Oracle Resource Manager. DBMS_RESOURCE_MANAGER is the packcage to administer the Database Resource Manager. The DBMS_RESOURCE_MANAGER package maintains plans, consumer groups, and plan directives. It also provides semantics so that you may group together changes to the plan schema. Q.You want users to change their […]

Oracle Interview Questions – Part 38

Q.How would you go about generating an EXPLAIN plan? Create a plan table with utlxplan.sql. Use the explain plan set statement_id = ‘tst1′ into plan_table for a SQL statement Look at the explain plan with utlxplp.sql or utlxpls.sql Q.How would you go about increasing the buffer cache hit ratio? Use the buffer cache advisory over […]