Performance - Andrew Calvett

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Exploring backup read io performance
24 January 2010 14:12
I was recently exploring how to increase the backup read throughput on one of our SQL servers. Below are some interesting facts i found. I would say that one of the most important reminders that came from the exercise is, do not assume that 2 databases being backup up on the same server using an identical backup command means that the processes are identical... Read More...
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Enter the SSAS server level lock......
23 November 2009 18:13
Ok, so your reaction to the title is probably the same as mine when i found out about SSAS server level locks! So, i will give you the scripts to reproduce the server level lock but first lets get down to business…. :) Server locks were introduced in one of the SP2 cumulative updates. At the moment i can say it was pre CU12. I`m not sure why it was introduced... Read More...
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The cost of SSAS metadata management
21 August 2009 06:45
This post will explain how we found ourselves in a situation where when processing a partition the metadata checks took 50 times longer than the actual partition and how to identify what time penalty you are incurring for the metadata checks. The system i was investigating had around 80 cubes with around 100 partitions per cube all hosted in one database and... Read More...
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Analysis Server appears to hang…..
05 April 2009 21:40
We had an ongoing problem where by users would suddenly start complaining that the Analysis Server was hanging. When investigating the box we could see that there appeared to be no physical constraints. Disks were a bit above average, CPU was very low and there was plenty of memory. When looking at the server through the SSAS activity viewer (part of the community... Read More...
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The evils of implicit conversions
18 January 2009 17:18
I wanted to put up a brief post showing the impact of an implicit conversion on the performance of a query (or not......). In the example i will show an implicit conversion negatively impacting query performance and an implicit conversion that does not impact performance..... So, we need to setup the test environment using the code below. SET ANSI_WARNINGS OFF... Read More...
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SSAS 2005 – Server side tracing starter kit
07 April 2008 22:32
Analysis services 2005 (SSAS) added the ability to trace server side events and i have used this feature a number of times. To date i had always used the profiler gui to do the SSAS tracing but today i found myself needing to initiate and manage a trace with scripts. The good news is that it can be done! It did take a while to piece together how to do it though... Read More...
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SQL 2005: Procedure cache cleared
05 June 2006 18:15
I don't normally write about a technet article but i must say that 917828 caught my eye and i felt that it was worth highlighting it. The reason it caught my eye is that it describes a number of scenarios where by the whole procedure cache is flushed which will clearly lead to a decrease in query performance whilst the cache builds up again. The most alarming... Read More...
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A performance analysis example
15 January 2006 17:53
Last week i was dragged kicking and screaming away from my allocated SQL 2005 days to spend 2 days diagnosing performance problems on one of the firms Systems and write a report. Due to the sensitive nature of the data on the system it has been managed by another team and this was the first time i had looked at it. I thought i'd share my thought process to identifying... Read More...
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