Please start any new threads on our new
site at https://forums.sqlteam.com. We've got lots of great SQL Server
experts to answer whatever question you can come up with.
| Author |
Topic |
|
haz33
Starting Member
15 Posts |
 Posted - 2007-12-18 : 09:47:14
|
| Hi, I'm hoping someone can help me with this.I have a view that combines multiple tables. There are about 36,000 rows in that view. One of the fields is an integer. If I select all of that field's values from the view, the data is returned in under a second. Likewise, if I do a COUNT or an AVG function on that field, the row is returned in under a second.Now, if I attempt to use the MIN or MAX function, all of a sudden, the query takes 22 seconds to run and return an answer. Why would this occur? Why are the COUNT and AVG functions so fast and the MIN and MAX functions so slow?I'm not terribly knowledgeable about using the Execution Plan within SQL Server, so if something needs to be done there, I might need a little guidance.Thanks in advance!-Erik |
|
|
visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2007-12-18 : 09:51:52
|
| Are you grouping on any field? |
 |
|
|
RickD
Slow But Sure Yak Herding Master
3608 Posts |
Posted - 2007-12-18 : 09:53:13
|
| Can you post your query? |
|
|
|
haz33
Starting Member
15 Posts |
Posted - 2007-12-18 : 09:56:40
|
| visakh16:I was grouping on a field originally. But even if I do a simple "SELECT MAX(field) FROM table", it still takes the same amount of time.RickD:There's really nothing to the query...select min(w_address) as Expr1 from d_wiring where r_name='TSR'I should note, however, that d_wiring is a view. |
|
|
|
visakh16
Very Important crosS Applying yaK Herder
52326 Posts |
Posted - 2007-12-18 : 10:08:20
|
| Can you view execution plans for AVG() & MIN MAX and see if there are any significant differences ( look for step with high query costs) |
|
|
|
haz33
Starting Member
15 Posts |
Posted - 2007-12-18 : 10:40:36
|
| It looks like I found it in the execution plan. I was calling a particular table more times than I needed to. Once I fixed the query, then the performance greatly improved.Thanks for the help! |
|
|
|
|
|
|
|
|
Poor performance with MIN and MAX functions