DBMS-Relational Query Languages
DBMS-Relational Query Languages
11. Codd's Formation rule states that:
- a relational database management system must manage the database entirely through its relational capbilities.
- null values are systematically supported independent of data type.
- all information is represented logically by values in tables
- None of these
12. Codd's View Update rule states that:
- the system should be able to perform all theoretically possible updates on views.
- the logical description of the database is represented and may be interrogated by authorised users, in the same way as for normal data
- the ability to treat whole tables as single objects applies to insertion, modification and deletion, as well as retrieval of data
- null values are systematically supported independent of data type.
13. Codd's system catalogue rule states that:
- the system should be able to perform all theoretically possible updates on views.
- the logical description of the database is rpresented and may be interrogated by authorised users, in the same way as for normal data.
- the ability to treat whole tables as single objects applies to insertion, modification and deletion, as well as retrieval of data.
- null values arre systematically supported independent of data type.
16. Which of the following is not a data definition statement ?
- INDEX
- CREATE
- MODIFY
- DELETE
17. Which of the following is a data query statement in QUEL
- GET
- RETRIEVE
- SELECT
- None of these
19. Codd's Non-subversion rule states that:
- entity andreferential integrity constraints should be defined in the high-level relational language referred to in Rule-5, stored in the system catalogues and enforced by the system, not by application programs.
- the ligical description of the database is represented and may be interrogated by authorised users in the same way as for normal data.
- if a low-level procedural language is supported, it must not be able to subvert integrity or security constraints expressed in the high-level relational language.
- the ability to treat whole tables as single objects applies to insertion, modification and deletion as well as retrieval of data
20. QUEL is a tuple relational calculus language of a relationall database system:
- INGRES
- DB2
- ORACLE
- None of these