Oracle perguntas e respostas de entrevista
Diferencas relacionadas
Pergunta 26. What is an Integrity Constrains?
An integrity constraint is a declarative way to define a business rule for a column of a table.
Pergunta 27. What is an Index?
An Index is an optional structure associated with a table to have direct access to rows, which can be created to increase the performance of data retrieval. Index can be created on one or more columns of a table.
Pergunta 28. What is an Extent?
An Extent is a specific number of contiguous data blocks, obtained in a single allocation, and used to store a specific type of information.
Pergunta 29. What is a View?
A view is a virtual table. Every view has a Query attached to it. (The Query is a SELECT statement that identifies the columns and rows of the table(s) the view uses.)
Pergunta 30. What is Table?
A table is the basic unit of data storage in an ORACLE database. The tables of a database hold all of the user accessible data. Table data is stored in rows and columns.
Mais uteis segundo os 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?