Oracle preguntas y respuestas de entrevista
Diferencias relacionadas
Pregunta 31. What are the advantages of views?
- Provide an additional level of table security, by restricting access to a predetermined set of rows and columns of a table.
- Hide data complexity.
- Simplify commands for the user.
- Present the data in a different perspective from that of the base table.
- Store complex queries.
Pregunta 32. What is an Oracle sequence?
A sequence generates a serial list of unique numbers for numerical columns of a database's tables.
Pregunta 33. What are synonyms used for?
- Mask the real name and owner of an object.
- Provide public access to an object
- Provide location transparency for tables, views or program units of a remote database.
- Simplify the SQL statements for database users.
Pregunta 34. What does a Control file Contain?
A Control file records the physical structure of the database. It contains the following information.
Database Name
Names and locations of a database's files and redolog files.
Time stamp of database creation.
Lo mas util segun los usuarios:
- What are the components of physical database structure of Oracle database?
- What are the components of logical database structure of Oracle database?
- What is a tablespace?
- What is SYSTEM tablespace and when is it created?
- Explain the relationship among database, tablespace and data file?