what is the difference between union and union all
Answer Posted / soubhagya
Union:
It retrieves only distinct records.
Union all:
This retrieves duplicate records too.
but in performance issue
unioun all is better becoz it doesnot sort, filter the
record so its faster.
Is This Answer Correct ? | 5 Yes | 0 No |
Post New Answer View All Answers
List the different type of joins?
What is row_number () in sql?
How to create an array in pl/sql?
How can I delete duplicate rows?
How run sql*plus commands that are stored in a local file?
How do I access sql anywhere database?
What is the use of sqldataadapter?
Explain the uses of control file.
Can we use loop in sql?
What are sql*plus environment variables?
What are the different types of triggers?
What is a record in pl/sql?
Why do we create stored procedures & functions in pl/sql and how are they different?
Is merge a dml statement?
What is sql key?