How It Works: Bob Dorr’s SQL Server I/O Presentation

I put a presentation together quite some time ago going over various SQL Server I/O behaviors and relating them to the SQL Server I/O whitepapers I authored.    I keep getting requests to post the presentation and the information is relevant from SQL 7.0 to SQL Server 2008 and beyond.  Here are the RAW slides and…

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DBMail has Suddenly Stopped Working

  The other day we ran into a strange Database Mail issue here in SQL support. Customers were running into issues where DBMail would suddenly stop working after doing service pack upgrades to their SQL Servers.This was happening on both SQL 2005 and SQL 2008. The error was also unusual in that the word “timeout” could make…

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How It Works: SQLIOSim CTRL+C vs Close Window

Today I had an interesting question about the CTRL+C handler for the SQLIOSim console execution.    After some investigation I found that a design change request is in order as the CTRL+C handler has a few holes-  (I am working on that part). The CTRL+C handler does not prompt you for something like ‘Do you wish…


How It Works: How many databases can be backed up simultaneously?

Previously I have posted details on backup/restore designs and how to tell what backup/restore is doing. http://blogs.msdn.com/psssql/archive/2009/03/03/how-it-works-sql-server-vdi-vss-backup-resources.aspx http://blogs.msdn.com/psssql/archive/2008/01/28/how-it-works-sql-server-backup-buffer-exchange-a-vdi-focus.aspx http://blogs.msdn.com/psssql/archive/2008/01/23/how-it-works-what-is-restore-backup-doing.aspx This post attempts to bring the concepts together to answer the question: "How many databases can be backed up simultaneously?"   The figure should look familiar as a combination of the previous posts.    The reason I…


Reduce locking and other needs when updating data – Better Performance

The following pattern typically stems from an old practice used in SQL 4.x and 6.x days, before IDENTITY was introduced. begin tran declare @iVal int select @iVal = iVal from CounterTable (HOLDLOCK) where CounterName = ‘CaseNumber’ update CounterTable set iVal = @iVal + 1 where CounterName = ‘CaseNumber’ commit tran return @iVal This can be…


SQL Server Cumulative Update or Service Pack Fails With – CREATE DATABASE failed

Here is a situation where a cumulative update patch can fail if the default database path for the data and/or log either does not exist, or there is a permissions issue.  This example is based on a SQL Server 2005 Cumulative Update 4 for SP3.  The problem can happen for any SQL Server 2000, SQL…

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An update for Standard SKU Support for Locked Pages….

Note this article has been updated to include an update for SQL Server 2005 I posted in April that we would be releasing cumulative updates for SQL Server 2008 and 2005 to support the concept of Locked Pages for SQL Server Standard. SQL Server 2008 Cumulative Update 2 for SP1 was released yesterday to provide…

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SSIS 2005 and the .NET Garbage Collector

I was troubleshooting an SSIS Out of Memory issue the other day which led us into how the .NET Garbage Collector (GC) works.  When debugging it, I found that we were using the Workstation GC with Concurrent GC On (this is the default for .NET applications).  The following blog discusses the different flavors of the…

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