performance question

Why does Query1 below have a Scan with 21 Logical Reads for 31 records
returned (a small percentage of Logicalreads), when Query 2 has no Scan,
only returns 6 records, and has 14 Logical reads. (a higher percentage)
In other words, the more data, the fewer Logical reads but no Scan. The less
data, higher reads but a scan. What gives?
SQL2K sp3a
TIA, ChrisR
what query? what data types are the columns?
2004 and 2005 Microsoft MVP C#
Robbe Morris
http://www.masterado.net
Earn $$$ money answering .NET Framework
messageboard posts at EggHeadCafe.com.
http://www.eggheadcafe.com/forums/merit.asp
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>
|||The scan on a clustered or nonclustered index at the leaf level is pretty
simple since it goes from leaf page to leaf page in order. It can read
relatively few pages to get a lot of rows that way. A seek has to traverse
the B-Tree from root to leaf level for each row returned. Depending on the
size of the index tree it can read a minimum of 2 pages per row seeked.
Andrew J. Kelly SQL MVP
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>

performance question

Why does Query1 below have a Scan with 21 Logical Reads for 31 records
returned (a small percentage of Logicalreads), when Query 2 has no Scan,
only returns 6 records, and has 14 Logical reads. (a higher percentage)
In other words, the more data, the fewer Logical reads but no Scan. The less
data, higher reads but a scan. What gives?
SQL2K sp3a
TIA, ChrisRwhat query? what data types are the columns?
--
2004 and 2005 Microsoft MVP C#
Robbe Morris
http://www.masterado.net
Earn $$$ money answering .NET Framework
messageboard posts at EggHeadCafe.com.
http://www.eggheadcafe.com/forums/merit.asp
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>|||The scan on a clustered or nonclustered index at the leaf level is pretty
simple since it goes from leaf page to leaf page in order. It can read
relatively few pages to get a lot of rows that way. A seek has to traverse
the B-Tree from root to leaf level for each row returned. Depending on the
size of the index tree it can read a minimum of 2 pages per row seeked.
--
Andrew J. Kelly SQL MVP
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>sql

performance question

Why does Query1 below have a Scan with 21 Logical Reads for 31 records
returned (a small percentage of Logicalreads), when Query 2 has no Scan,
only returns 6 records, and has 14 Logical reads. (a higher percentage)
In other words, the more data, the fewer Logical reads but no Scan. The less
data, higher reads but a scan. What gives?
SQL2K sp3a
TIA, ChrisRwhat query? what data types are the columns?
2004 and 2005 Microsoft MVP C#
Robbe Morris
http://www.masterado.net
Earn $$$ money answering .NET Framework
messageboard posts at EggHeadCafe.com.
http://www.eggheadcafe.com/forums/merit.asp
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>|||The scan on a clustered or nonclustered index at the leaf level is pretty
simple since it goes from leaf page to leaf page in order. It can read
relatively few pages to get a lot of rows that way. A seek has to traverse
the B-Tree from root to leaf level for each row returned. Depending on the
size of the index tree it can read a minimum of 2 pages per row seeked.
Andrew J. Kelly SQL MVP
"ChrisR" <noemail@.bla.com> wrote in message
news:OLWXZnMiFHA.3672@.TK2MSFTNGP10.phx.gbl...
> Why does Query1 below have a Scan with 21 Logical Reads for 31 records
> returned (a small percentage of Logicalreads), when Query 2 has no Scan,
> only returns 6 records, and has 14 Logical reads. (a higher percentage)
> In other words, the more data, the fewer Logical reads but no Scan. The
> less data, higher reads but a scan. What gives?
> SQL2K sp3a
> TIA, ChrisR
>

Performance Monitor log files

For the SQL Server running here we have setup a log file that monitors all the activities while the server is running, such as processor percentage being used over the day, CPU percentage taken by SQL Server etc. The problem I'm facing is that the log files (which are in PERFMON format) are recorded over a period of a business day for 30 days. Now I want to get the measurements for all the 30 days combined into one file where i can analyze all the measurement over 30 days.

Thanks in advance.HI

I dont know of any way to combine log files. The best you can do is establish numeric values then manually put these into a spreadsheet if you want a graph.

In future, just run the perfmon monitoring for 30 days......

Hope this helps,

SG