Solved

LATCH_EX with CXPACKET causing query performance degradation

Posted on 2009-05-13
1
1,935 Views
Last Modified: 2012-06-27
SQL Server 2000 SP4 Build 2187. When runing simple SELECT query with INNER joins causing LATCH_EX waittype with huge number of CXPACKET causing consistent high CPU with performance degradation. Indexes are in place with stats updated. Moving data files to different disk didn't make any difference. Execution plans are changing with and without 'TOP' clause. With 'TOP' clause plans are generating with 'INDEX SEEK, Nested Loop' while without 'TOP' clause changing to 'INDEX SCAN, Table Spool, Hash Match, Merge Join'. WHY? Can anyone give some action plan?
0
Comment
Question by:info2rafiq
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 51

Accepted Solution

by:
Mark Wills earned 500 total points
ID: 24381764
Hi info2rafig,  

sounds like some I/O problems maybe...

Are you running profiler by chance ? http://support.microsoft.com/kb/929728

There is a fairly high level overview of wait types and what to look for : http://www.sqldev.net/misc/waittypes.htm

A fella by the name of Thomas Davidson is the guru on 2000 performance. There is a whitepaper floating around, but his presentation is a bit more graphic : http://www.sqldev.net/events.htm#SQL_Connections_12-15_October_2003,_Palm_Springs_CA_  look for the one in the middle : SPR-201-4

Apologies about all the links, but performance is a minefield potentially, and best to understand what might be causing it first. So, have a look and read, and then come back with some more questions if needed - OK ?
0

Featured Post

Free Tool: Subnet Calculator

The subnet calculator helps you design networks by taking an IP address and network mask and returning information such as network, broadcast address, and host range.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Force application to connect using sql native client for mirroring 3 20
Creating a View from a CTE 15 49
SQL Server Agent "Access Denied" Error 3 36
T-SQL Query 9 37
Why is this different from all of the other step by step guides?  Because I make a living as a DBA and not as a writer and I lived through this experience. Defining the name: When I talk to people they say different names on this subject stuff l…
Ever needed a SQL 2008 Database replicated/mirrored/log shipped on another server but you can't take the downtime inflicted by initial snapshot or disconnect while T-logs are restored or mirror applied? You can use SQL Server Initialize from Backup…
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the SELECT statement in SQL and will be exposed to the many uses the SELECT statement has.

752 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question