DBMS interview

1. Indexing must be applied on fields that are
a. seldom refernced in query
b. containing few unique columns
c. on frequently searched columns
d. changed frequently
3. The relational data model includes several types of data integrity .which type of data integrity is ensured by the use of a primary key?
a. entity integrity
b. domain integrity
c. referential integrity
d. relational integrity
4. a student has 3 diff. Teachers . Each of these teachers has several students. Which type of relationship in relation model would effective represent this?
a. 3 one-to-many relationships
b. two many-to-one relationships
c. a single many-to –many relationshjips
d. at least 2 many-to-many relationships
5. which of the following properties are required of a column or column sets for the column to function as a primary key?
a. no nulls
b. a clustered index
c. a non-clustered index
d. ther must be atleast 1 foreign key on tha same table.
7. select, fn,, from a, b, c wher
tables a,b,&c each contain 100 rows & the primary key for tables a & b is pk. What is the maxm. No. of rows that could be returned by query
a. 100
b. 0
c. 100,000
d. 10,000
e. 1,000,000
8. which of the following is only used with a foreign key constraint ?
a . primary key constraint
b. the refereces clause
c. a check constraint
9. which is used to return the no. of rows in a table?
a. sel;ect all count from tablename
b. select count(*) from tablename
c. select numrows from table name
11. when writing sql queries , how do u control the query execution plan used by the databases
a. query directly against an idex instead of table
b. define a static cursor & specify the “using specific index’ keyword
c. most databases provide propreitory methods to give database hint
d. enclose quey in atransaction & add a statement using the “set search” keyword
14,. Which is not allowed in a trigger
a. update
b. select into
c. while
d. begin type, avg(price), min(price) from product group by category
what is wrong??
a. u can’t include multiple aggregates in a select list
b. there is no where clause
c. nothing