Re: indexes and selects
- From: "MikeJ" <analizer1@xxxxxxxxx>
- Date: Fri, 19 Oct 2007 12:39:39 -0700
thanks alot Russel...i will read the books online...
thanks again
Mike
"Russell Fields" <russellfields@xxxxxxxxxx> wrote in message
news:upGH$PoEIHA.1212@xxxxxxxxxxxxxxxxxxxxxxx
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
.
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