Subject | Select * from where 0=1 |
---|---|
Author | Jerome Bouvattier |
Post date | 2004-03-24T10:51:05Z |
Hello list,
I need to retrieve an empty resultset with all fields of a given table. I
tried the two following queries :
#1 : Select * from <table> where 0=1
#2 : Select first 0 * from <TableName>
First one seems to care about the amount of data in the queried table, while
the second one does not.
Against an empty table, both queries perform the same.
On a 15 million table, #1 takes 1.8s while #2 takes 20ms.
I need to come up with a statement that's as fast a #2 but also works on
most IB/FB engines.
How should this statement look like ?
Thanks in advance.
--
Jerome
I need to retrieve an empty resultset with all fields of a given table. I
tried the two following queries :
#1 : Select * from <table> where 0=1
#2 : Select first 0 * from <TableName>
First one seems to care about the amount of data in the queried table, while
the second one does not.
Against an empty table, both queries perform the same.
On a 15 million table, #1 takes 1.8s while #2 takes 20ms.
I need to come up with a statement that's as fast a #2 but also works on
most IB/FB engines.
How should this statement look like ?
Thanks in advance.
--
Jerome