Union or union all...tough task

[holdingbe]

Hi all,

I execute union scripts.. it will take long time but i use union all instead of union i got output at very short time..I don't know how to eliminate the duplicate rows using union all....
Please help me

[debasisdas]

try using DISTINCT , that might help

[holdingbe]

try using DISTINCT , that might help

i used distinct but the sam time will be taken

[debasisdas]

could u kindly post your query with table structure please, for my reference.

[holdingbe]

could u kindly post your query with table structure please, for my reference.

Sorry, i unable to give the table structure

[debasisdas]

same here

Sorry ,i am unable to give you the answer.

[sarehaman]

Hi all,

I execute union scripts.. it will take long time but i use union all instead of union i got output at very short time..I don't know how to eliminate the duplicate rows using union all....
Please help me

Union
checks the each and every row ..
whether any duplicate row are existing in the database
and avoid them before returns the rows .. for this entire process takes the time..
but in Union all
Can't take risk to check for duplicate.
So its returns all row which are returned from the query...
okay

good luck