ORACLE INTERVIEW QUESTION & ANSWERS
| 41. |
Define constraints? |
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- Constraint is a rule or restriction concerning a piece of data that is enforced at the data level rather than the object or application level.
- A constraint clause can constraint a single column or group of columns in a table.
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| 42. |
What are the different types of constraints? |
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There are five types of constraints namely are : - Null / Not Null
- Primary Key
- Unique
- Check or Validation
- Foreign key or References key
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| 43. |
What is the different types of constraint clause? |
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Constraint clause can be divided in two levels are : - Table constraint
- Column constraint
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| 44. |
What is the primary duty of the DBA? |
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The primary duty of the DBA is to protect the database and provide continuous (if required) access to that data for the user community. |
| 45. |
What is a Tablespace? |
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A database is divided into Logical Storage Unit called tablespace. A tablespace is used to grouped related logical structures together. |
