Answer Posted / surendra reddy duggireddy
Identity Columns generate a system-generated number for
every row as it is inserted
in the table. It is also knows as a DBS Generated Unique
Primary Index. Identity
Columns are used if you want to guarantee row uniqueness in
a table and they can
simplify the initial port from databases other than
Teradata. They are often used as the
Primary Index so they can guarantee even distribution. In
some cases they are utilized to
optimize and simplify the first port from another database
that uses generated keys.
Identity columns do NOT need to be part of the Primary
Index, but they are often used
for that purpose because they provide even data
distribution. The biggest rule is that
you can only specify one Identity Column per table
Example:
-------
Create Table Employee_Table
( Employee_No INTEGER
GENERATED ALWAYS AS IDENTITY
(START WITH 1 INCREMENT BY 5
MAXVALUE 1000000
NO CYCLE)
, Dept_No INTEGER
,First_Name CHAR(20)
,Last_Name CHAR(20)
,Salary DECIMAL (10,2)
) PRIMARY INDEX (Employee_No);
| Is This Answer Correct ? | 8 Yes | 0 No |
Post New Answer View All Answers
Highlight a few of the important components of Teradata?
What are the components provided on node?
What is the difference between union and union all in teradata?
How would you load a very large file in teradata in general?
What are the various indexes in teradata? Why are they preferred?
What are the available primary index types?
What is stored procedure in teradata?
What are the uses of bynets in multi-node systems?
Can we have two time dimensions in a schema(either star or snow flake)? For ex if we want joining date of employee and if we want today's sales with time whether can we have two time dimensions for accommodating above tasks?
A certain load is being imposed on the table and that too, every hour. The traffic in the morning is relatively low, and that of the night is very high. As per this situation, which is the most advisable utility and how is that utility supposed to be loaded?
What are the joins in teradata and how many types of joins are there in teradata?
What are the steps to create a data model?
How do you create tables? Exact syntax, and create profiles, users in teradata?
What are different table types used in teradata?
Explain Teradata performance tuning and optimization?