Technology Questions

Layer objects are data objects which represent visual content. Layer objects are used by views to render their content. Custom layer objects can also be added to the interface to implement complex animations and other types of sophisticated visual effects.

Primary key constraint ensures that the column(s) always has a unique value to identify the record.
Example:
Below, the primary key is created for column id with name prim_id.
create table employee ( id number NOT NULL, Name varchar(200) Constraint prim_id primary key(id) );

Regression Testing: When changes in the code of the software are made to fix the previous bug. Then testing needs to be perform to ensure that it will not generate a new bug in the application and it works as specified and that it has not negatively impacted any functionality that it offered previously. Regression Testing is important because of following reason:

- That the application works even after the alteration in the code were made.

- The original functionality continues to work as specified even after doing changes in the software application.

- The alteration to the software application has not introduced any new bugs.

- These are the Logical Storage Units into which a database is divided.
- It is used to group together the related logical structures.

Each application gets its own Linux user ID and virtual machine which means that the application code runs in isolation from other applications.