In SQL Server, the cost of a particular plans is based largely on I/O, which makes this post a good candidate for this month’s T-SQL Tuesday, hosted by Mike Walsh who, like me, walks a straight path. In considering I/O – the movement of data generally In and Out of disk and memory – my thoughts come very much to query cost. If I run set ...

I've been working on my presentation for SQL Saturday in Charlotte - http://www.sqlsaturday.com/33/eventhome.aspx . I will be presenting a session on using the basics of Perfmon to monitor your environment. There is a great line-up of speakers. If you...(read more)

Brent Ozar ( blog | twitter ) recently made some comments about the FusionIO SSD drives . Basically, he was able to break three drives in a row - simply by doing load testing against them ( using SQLIO ). The symptom is simple: the drives go offline and...(read more)

I just read in a forum about a user who want to replikate a table, but the table doesn't have a PK. The table is pretty large, and having the table not available while adding the PK is undesireable. The table has a clustered index already, and there are...(read more)

I recently read a discussion whether RPC events add overhead compared to just submitting text. I got curious and did some testing, which I want to share. Background, SQL events Using most APIs, if you just submit a query to SQL Server, you will get what...(read more)

Let's start with some background on forwarding pointers: Forwarding pointers in heaps can be a mess to get rid of. A forwarding pointer happens when you modify a row so that the row doesn't fit on the same page anymore. SQL Server moves the row to a new...(read more)

My latest MSDN column is available in the August issue and called "How Data Access Affects Database Performance". It was inspired by a problem that one of my DBA friends noticed in the database that could only be fixed by changing the data access code. I noticed that there were two articles in the issue on EDM and, although ...

During a talk about spatial indexes and performance last week, I was surprised by a question about using ANSI-92 JOIN - ON syntax in spatial queries. I'd coded: SELECT * FROM geonames.dbo.geonames g JOIN Sample_USA.dbo.Counties c   ON g.GEOG.STIntersects(c.geog) = 1 WHERE c.ID = 1569 Later I learned that the question ...

I see a trend towards more and more focusing on response time; and less and less on resource usage (resource consumption). I've even seen blanket statements such as the only thing that matters is response time. I do not agree. I feel that by being a good citizen and consume as few resources and possible, we contribute to the overall welfare of the ...

Recently, I needed to capture some performance data from the host of a virtualized SQL Server.  There is a utility called ''esxtop'' that if run from the ESX Host Command Line, it displays text-based information in columns similar to that which you see in Windows Task Manager.  That is handy, but I wanted to get this to a file.  ...