What is the difference between SYNONYM and ALIAS?
- 6 Answers
- 26389 Views
- TCS, I also Faced
- E-Mail Answers
Answer Posted / s
SYNONYM and ALIAS are alternate names to a table. A SYNONYM
is dropped when the table is dropped whereas an alias is
not dropped if the table it is defined on is not dropped.
| Is This Answer Correct ? | 26 Yes | 17 No |
Post New Answer View All Answers
SET is the ANSI standard for variable assignment, SELECT is not. SET can only assign one variable at a time, SELECT can make multiple assignments at once. If assigning from a query, SET can only assign a scalar value. If the query returns multiple values/rows then SET will raise an error. SELECT will assign one of the values to the variable and hide the fact that multiple values were returned (so you'd likely never know why something was going wrong elsewhere - have fun troubleshooting that one) When assigning from a query if there is no value returned then SET will assign NULL, where SELECT will not make the assignment at all (so the variable will not be changed from it's previous value) As far as speed differences - there are no direct differences between SET and SELECT. However SELECT's ability to make multiple assignments in one shot does give it a slight speed advantage over SET.
Can there be more than one cursor open for any program?
before altering a table is it necessary to lock ? if lock what is it ? how to do ? ifi want to lock a table what is that command ?
Mention the definition of cobol in varchar field.
Mention the different locking levels that are available in db2.
How to access db2 tables in mainframe?
How does coalesce work?
Define check constraint.
What is db2?
What is the syntax for creating a table in the db2 database?
What is null in db2?
Name the various locking levels available?
What are the different types of base tables?
What is phantom read in db2?
Can we delete records from view?
