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From:Brent Baisley Date:July 28 2004 1:17pm
Subject:Re: Indexed Database still slow
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Your problem is that you created a single index. An index is just a 
presorted list of the data. The first column in the index is the most 
relevant, being sorted by that column first.  If you have an index on 
State+County+Town, how would you quickly find a town? You can't if you 
don't know the State or County, because the data is sorted first by 
State, then by County, then by Town.
You need to create a separate index for each column you are searching 
on. The only time you will create an single index containing multiple 
columns is if you will always be searching on the indexed fields in the 
order you declared them in your index (i.e. State+County).

On Jul 28, 2004, at 8:25 AM, christopher.l.hood@stripped wrote:

> Ok, I will be the first to say that I am learning about indexes, 
> however
> it is my understanding that if I have a database with MANY rows and I
> wish my queries to be faster I should index my database. With that 
> being
> said, I have 2 tables in my database that are being queried with a
> single query using a UNION these 2 tables combined are about 9 Million
> records (yes I said million).
>
> My query which is below takes about 1 minute to run, now some people
> would say that this isn't long, however when the 2 tables were sub 5
> million it only took a matter of about 20 seconds to run, so I figure I
> need an index. So I have created an index called "Main" within both
> tables and added 6 columns to that index, most of the columns that are
> used in my query.
>
> Sorry for the long background, but here is the problem, my query DID 
> NOT
> speed up at all. It still takes right at 1 minute per query, so 
> indexing
> didn't buy me anything as far as I can tell.
>
> Can someone tell me how the indexes are supposed to be done ( to ensure
> that I did it correctly) and tell me if they think that it should have
> sped up or if there is a more efficient way to do my query.
>
>
> ###QUERY HERE ###
>
> Select ALL PRTC_DIALUP.Id, PRTC_DIALUP.Date, PRTC_DIALUP.Time,
> PRTC_DIALUP.Record_Type, PRTC_DIALUP.Full_Name,
> PRTC_DIALUP.Framed_IP_Address
> from PRTC_DIALUP
> Where PRTC_DIALUP.Framed_IP_Address = 'someipaddress' AND
> (PRTC_DIALUP.Date = 'one-date-here' OR PRTC_DIALUP.Date =
> 'one-day-earlier' OR PRTC_DIALUP.Date = 'one-day-later')
> UNION
> Select ALL PRTC_DSL.Id, PRTC_DSL.Date, PRTC_DSL.Time,
> PRTC_DSL.Record_Type,  PRTC_DSL.Full_Name, PRTC_DSL.Framed_IP_Address
> from PRTC_DSL
> Where PRTC_DSL.Framed_IP_Address = 'someipaddress' and (PRTC_DSL.Date =
> 'one-date-here' OR PRTC_DSL.Date = 'one-day-earlier' OR PRTC_DSL.Date =
> 'one-day-later')
> order by Full_Name, Time;
>
> ### END QUERY ###
>
> Chris Hood
> Investigator Verizon Global Security Operations Center
> Email:  <mailto:christopher.l.hood@stripped>
> christopher.l.hood@stripped
> Desk: 972.399.5900
>
> Verizon Proprietary
>
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-- 
Brent Baisley
Systems Architect
Landover Associates, Inc.
Search & Advisory Services for Advanced Technology Environments
p: 212.759.6400/800.759.0577

Thread
Indexed Database still slowchristopher.l.hood28 Jul
  • Re: Indexed Database still slowBrent Baisley28 Jul
    • Re: Indexed Database still slowSGreen28 Jul
  • Re: Indexed Database still slowSGreen28 Jul
    • Re: Indexed Database still slowDan Nelson28 Jul
  • Re: Indexed Database still slowEgor Egorov29 Jul
RE: Indexed Database still slowchristopher.l.hood28 Jul