Message from discussion
Performance Issue
Thread-Topic: Performance Issue
thread-index: AcbZBo9JnXoTwJRgSWOORg9es6CVhg==
X-WBNR-Posting-Host: 65.125.177.4
From: =?Utf-8?B?Q2hyaXM=?= <Ch...@discussions.microsoft.com>
Subject: Performance Issue
Date: Fri, 15 Sep 2006 13:36:02 -0700
Lines: 39
Message-ID: <0D4EA01E-209A-4654-BF81-8B85BAF147CF@microsoft.com>
MIME-Version: 1.0
Content-Type: text/plain;
charset="Utf-8"
Content-Transfer-Encoding: 7bit
X-Newsreader: Microsoft CDO for Windows 2000
Content-Class: urn:content-classes:message
Importance: normal
Priority: normal
X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.1830
Newsgroups: microsoft.public.sqlserver.programming
NNTP-Posting-Host: TK2MSFTNGXA01.phx.gbl 10.40.2.250
Path: g2news2.google.com!news3.google.com!news2.volia.net!npeer.de.kpn-eurorings.net!newsfeed.cw.net!cw.net!news-FFM2.ecrc.de!TK2MSFTFEEDS02.phx.gbl!TK2MSFTNGP01.phx.gbl!TK2MSFTNGXA01.phx.gbl
SQL2000 Std Ed.
Customers table 4 million records
Users search by phone# - during periods of heavy use the cpu will peg to
100% and searches will take 20+ seconds.
Here's the facts:
- where cluase uses '... where fPhone like @TelNo '
- No blocking, stored proc uses (nolock) isol. level.
- Query plan uses index on fPhone field - total cost 1.895 and less w/ the
more numbers entered in search.
- No to < 5% fragmentation - rebuilt when at 5% or greater
- Run profiler - see duration at 20000 milliseconds (rules out the network -
def. db)
- For long running spid - run sp_lock and see TAB lock on customers table
Was troubleshooting w/ user - user app in asp connecting w/ ado over oledb -
I was witnessing user spid taking 20+ seconds, I would grab exact same query
in profiler and run in Query Analyzer - it would take 1 seconds in QA - user
runs again 20 seconds, I run in QA - 1 to 2 seconds. User runs same again -
20 seconds - data cache not speeding things up.
I am assuming the app is getting stuck on a procedure cache that somehow
ignores the index on fPhone and does table scan - searches with 2 or 3
numbers do table scan - searches where all 7 numbers entered - index used.
Perhaps 1 user enters 3 numbers to search on - table scan query plan saved in
cache - next user searches by 7 numbers - db uses query plan w/ table scan.
Is this table lock escalation - is that common during periods of high
activity?
Any ideas how to combat?
Thanks,
Chris
|
