Database - Advanced SQL - Discussion
Discussion Forum : Advanced SQL - General Questions (Q.No. 7)
7.
Which of the following is true concerning systems information in an RDBMS?
Discussion:
3 comments Page 1 of 1.
Dhanashri said:
1 decade ago
A relation is defined as a set of tuples that have the same attributes.
A tuple usually represents an object and information about that object. Objects are typically physical objects or concepts. A relation is usually described as a table, which is organized into rows and columns. All the data referenced by an attribute are in the same domain and conform to the same constraints. The relational model specifies that the tuples of a relation have no specific order and that the tuples, in turn, impose no order on the attributes. Applications access data by specifying queries, which use operations such as select to identify tuples, project to identify attributes, and join to combine relations. Relations can be modified using the insert, delete, and update operators. New tuples can supply explicit values or be derived from a query. Similarly, queries identify tuples for updating or deleting. Tuples by definition are unique. If the tuple contains a candidate or primary key then obviously it is unique, however, a primary key need not be defined for a row or record to be a tuple. The definition of a tuple requires that it be unique. The definition does not require a Primary Key to be defined. The attributes of a tuple may be referred to as a super key.
Above all options are basically valid for RDBMS, thats why this answer is correct.
A tuple usually represents an object and information about that object. Objects are typically physical objects or concepts. A relation is usually described as a table, which is organized into rows and columns. All the data referenced by an attribute are in the same domain and conform to the same constraints. The relational model specifies that the tuples of a relation have no specific order and that the tuples, in turn, impose no order on the attributes. Applications access data by specifying queries, which use operations such as select to identify tuples, project to identify attributes, and join to combine relations. Relations can be modified using the insert, delete, and update operators. New tuples can supply explicit values or be derived from a query. Similarly, queries identify tuples for updating or deleting. Tuples by definition are unique. If the tuple contains a candidate or primary key then obviously it is unique, however, a primary key need not be defined for a row or record to be a tuple. The definition of a tuple requires that it be unique. The definition does not require a Primary Key to be defined. The attributes of a tuple may be referred to as a super key.
Above all options are basically valid for RDBMS, thats why this answer is correct.
Hari krishna dondapati said:
1 decade ago
The purpose of RDBMS is to store the information with high security. Here we can store information in the form of tables.
This is the standard database object for every rdbms tool.
Whatever information stored in the database, we can retrieve by using some proper commands like DQL.
Sql is the combination of DDL, DML, DQL, DCL, TCL.
Yeah, by applying locks or triggers we can not update the records.
This is the standard database object for every rdbms tool.
Whatever information stored in the database, we can retrieve by using some proper commands like DQL.
Sql is the combination of DDL, DML, DQL, DCL, TCL.
Yeah, by applying locks or triggers we can not update the records.
Asha said:
1 decade ago
Yes of course we have to apply the locks for avoiding updation of records. But the option C is not not correct for it.
It is the important aspect of RDBMS to allow owner to add, delete and modify the database.
For option C to correct they should mention proper question.
It is the important aspect of RDBMS to allow owner to add, delete and modify the database.
For option C to correct they should mention proper question.
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