Interview Questions

Dropped tables can be recovered using DROP TABLE flashback. It works the way recycle bin works.
Example:
FLASHBACK TABLE EMPLOYEE TO BEFORE DROP;
The most recently dropped table with that original name is retrieved from the recycle bin, with its original name.

The QA testing process that was followed in my last company where I worked was like this: First of all the Business Requirement Document was prepared as per the client’s requirement (with the muck-up screen shots). Then on the basis of the requirement document, Test Strategy, Test Plans and Test Cases were written in sequential order. Once the Build is made and deployed to the different testing environments where different types of testing were performed to check whether there are any defects.

READNEXT reads the next record from a browse operation for any of the three VSAM files.

Oracle constraints are used to maintain consistent of data and ensure the data is properly maintained. A constraint is more or less a restriction we try to apply on a table.
Types of constraints:
- Check constraints
- NOT NULL constraint
- PRIMARY KEY constraint
- REFERENCES constraint
- UNIQUE constraint

AWB stands for Administrator WorkBench. AWB is a tool for controlling, monitoring and maintaining all the processes connected with data staging and processing in the business information whearhousing.

- The process of combining data from different resources.

- The combined data is provided to the users with unified view.

- Information from different enterprise domains are integrated – known as Enterprise Information Integration.

- Useful for merging information from different technologies among enterprises.

- The sub areas of data integration are 

1. Data Warehousing.

2. Data Migration.

3. Master Data Management.

The System.Collections namespace contains all the collection classes.

The following are the areas of concern for tuning:

- Memory Usage

- Data Storage

- Data Manipulation

- Physical Storage

- Logic Storage

- Network Traffic

Tuning Memory Usage: In Oracle 10g, we can use the Automatic Workload Repository (AWR) toolset to gather and manage statistical data but in case of Oracle 11g, we can use new initialization parameters such as MEMORY_TARGET to further control the overall memory used by Oracle. It helps us to tune the database automatically when we don’t have time to read the AWR report.

Tuning Data Manipulation: There are two ways to tune Data manipulation in Oracle one way is through Conventional Path mode and second is Direct Path mode.

Tuning Physical Storage: We need to tune the physical storage because it limits the disk in database. This can be done by: Distributing I/O, Striping and Mirroring.