Subject | Weird performance problem |
---|---|
Author | tdtappe |
Post date | 2004-07-22T07:10:57Z |
Hi folks,
today I noticed some strange "performance behaviour".
I ran a SELECT command like
SELECT ID, ... FROM SomeTable WHERE ID = SomeID
on a database running in CS mode (FB 1.0.3) on a Linux box. The
client was W2K.
It was rather slow. 500ms execution time.
Running the same command from a different client on the same server
and database returned after 20ms.
This is reproducable.
Running the same command on the same database (backup/restore) on a
different Linux box returned after 20ms.
Now it starts to get funny:
Running "almost" the same command on the original server and database
gave me 20ms!?
What did I change?
The original command contained 43 columns. I just added another ID
column at the end of the column list.
That's all.
The same thing happens when I reduce the number columns to
42 (the answer to everything ;-)
or less.
BTW, the overall number of columns of the table is 43!
And so it's probably no surprise that "SELECT * FROM SomeTable" is
also slow.
Very strange.
Any idea?
--Heiko
today I noticed some strange "performance behaviour".
I ran a SELECT command like
SELECT ID, ... FROM SomeTable WHERE ID = SomeID
on a database running in CS mode (FB 1.0.3) on a Linux box. The
client was W2K.
It was rather slow. 500ms execution time.
Running the same command from a different client on the same server
and database returned after 20ms.
This is reproducable.
Running the same command on the same database (backup/restore) on a
different Linux box returned after 20ms.
Now it starts to get funny:
Running "almost" the same command on the original server and database
gave me 20ms!?
What did I change?
The original command contained 43 columns. I just added another ID
column at the end of the column list.
That's all.
The same thing happens when I reduce the number columns to
42 (the answer to everything ;-)
or less.
BTW, the overall number of columns of the table is 43!
And so it's probably no surprise that "SELECT * FROM SomeTable" is
also slow.
Very strange.
Any idea?
--Heiko