Re: indexes and selects

Mike,

The index stores values in separate columns and is ordered by the columns in
the order defined. That is, in your case
1 accountNo
2 FirstName
3 last name
4 dateOfTrans

There is additional structural information for the index, of course. This
index is ordered to work for queries that have the accountNo, the accountNo
and FirstName, and so on. However, sometimes the index will be used for
queries that do not have the accountNo just because the narrow index rows
may have lower I/O overhead than scanning the data or using multiple
indexes.

The issues of indexes are complex. The Books Online (2000 and 2005) have
good explanations on the topic that probably gives you everthing you need to
know. If you want to know more details on the internals, you can get the
book: Inside Microsoft SQL Server 2005: The Storage Engine
http://www.microsoft.com/MSPress/books/7436.aspx

RLF

"analizer1" <analizer1@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:1CB32BA5-F177-4587-8EA1-3E4FB1E87755@xxxxxxxxxxxxxxxx
Im trying to figure out the best way and/or fastest way to Match some data
comming in....example below
the below is all the incomming information i recieve to match to a row in
our system, we do send out a TransactionId but reports comming
back in do not reflect this id.. so i have to match the data. Matching is
pretty easy enough, but only been working with SqlServer about a Year now
and the existing system well Sucks on matching, so i want your advice and
the best way and fastest way to match up rows
with a high percentage..

when building a Index for the below , does sql store the data being
indexed
in separate columns
or are the Columns being indexed concatenated via the column order being
sorted

all you input i very welcome
tks
Mike


--not a key column
accountNo account of incomming partners customer
FirstName account holder first name
last name account holder last name
dateOfTrans account holder Transaction date






.