What is the difference between primary key & unique index ?
Answer Posted / mani
Primary key can be defined only one for a table whereas
number of unique indexes can be defined for a table.
primary key can not have null values but unique can have
null values and to remind one null value can never be equal
to another null value.
Is This Answer Correct ? | 23 Yes | 4 No |
Post New Answer View All Answers
Explain the function of data manager.
Which isolation level provides highest data integrity?
What is the use of runstats in db2?
Explain in brief how does db2 determine what lock-size to use?
in my project..TEST is db2 8.1 version In PROD it is 7.1 if i do REORG in TEST.. can I use the same REORG jcl with out modification in PROD region (this is DB2 8.1 )? if not, what modification i need to do in my REORG control card?
Explain dclgen.
How would the varchar column remarks defined?
What is a collection in db2?
What is the difference between db2 and oracle?
What is role in db2?
What is plan in cobol db2?
How do you concatenate the firstname and lastname from emp table to give a complete name?
My sql statement select avg(salary) from emp yields inaccurate results. Why?
What is difference between alias and synonym in db2?
List out the data types available.