Dell Oracle Placement Papers - Dell Oracle Interview Questions and Answers
Q1. What Is An Oracle Index?
An index is an optional shape associated with a desk to have direct get admission to to rows, which can be created to boom the overall performance of information retrieval. Index can be created on one or greater columns of a desk.
Q2. What Is Using Clause And Give Example?
He USING clause is used to specify with the column to check for equality whilst tables are joined.
[sql]Select * from table1 be part of table2 using table1 ID[/sql]
table1 tables be a part of with the table2 tables with the tableID.
Q3. What Is Hash Cluster?
Hash Cluster is a method used for storing the table to make it quicker to retrieve. It order to retrieve the rows from the table, observe the hash value on the table.
Q4. What Is Hot Backup And How It Can Be Taken?
Hot backup is taking backup of archived log documents whilst database is open.THe ARCHIVE LOG transfer need to be enabled for this to manifest. Hot backup takes place at the same time as the database continues to be being accessed by means of users and tables are being up to date. It does now not want the database to have a downtime.
Q5. What Is The Fastest Query Method To Fetch Data From The Table?
You can use ROWID to fetch Row from the table. The use of ROW ID is the fastest query approach for fetching information from the table.
Q6. What Is The Purpose Of Save Points In Oracle Database?
Save Points are used to divide a traction into smaller phases.
It enables rolling back a part of a traction.
Maximum five store points are allowed in Oracle Database.
Whenever an blunders is encountered, it's miles viable to rollback from the factor wherein the SAVEPOINT has been stored.
Q7. What Is The Use Of Aggregate Functions In Oracle?
Aggregate function is a characteristic in which values of more than one rows or facts are joined together to get a single fee output.
Common mixture functions are :-
Average
Count
Sum
Q8. What Is A System Tablespace And When It Is Created?
When the database is created in Oracle database system, it automatically generate a SYSTEM named SYSTEM tablespace. The SYSTEM tablespace contains statistics dictionary tables for the entire database.
Q9. What Are The Components Of Physical Database Structure Of Oracle Database?
Components of physical database shape are given underneath:
One or more facts files.
Two or more redo log documents.
One or more manipulate documents.
Q10. Explain The Function Of Optimizer In Oracle?
The optimizer determines the most green manner to execute a SQL statement based at the kind of data within the table and the statements fired to fetch that information like indexes, full table sc, loops, joins and so forth. Optimizers also are used to keep away from immoderate I/O assets.
