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Scan count

Hi,

Can someone please explain the following

1. Meaning of scan count as reported when "statistics io" is turned on
prior to running a query.

2. In which situations could you have an identical database running
on two diferent servers , with identical database server
configurations, running identical queries, with identical query plan,
report large discrepency in the scan count . This is one of the
possibilities we are looking at in terms of the reason why one server
runs the job in 12 hours and the other in 24 hours.

Server 1
--------
Table 'TRANS_HISTORY'. Scan count 216, logical reads 897093, physical
reads 44, read-ahead reads 900599.

SQL Server Execution Times:
CPU time = 27766 ms, elapsed time = 46850 ms.
UNIT_NUMBER ACCOUNT_TYPE TRANSACTION_TYPE
Server 2
--------

Table 'TRANS_HISTORY'. Scan count 491, logical reads 952759, physical
reads 51, read-ahead reads 954414.

SQL Server Execution Times:
CPU time = 31563 ms, elapsed time = 145595 ms.
UNIT_NUMBER ACCOUNT_TYPE TRANSACTION_TYPE

I thank you in advance for your assistance.

Puvendran
Jul 23 '05 #1
1 3781
Scan count is the number of times that the table was accessed in order
to get records. As for your second question, the number of scan count
and reads depends on the data that you have on the server,
fragmentation in the database, hardware, server level configuration,
database level configuration etc', so it is hard to say the exact
reason for those 2 completely different figures.

Adi

Jul 23 '05 #2

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