When I’m at the PASS Summit in Seattle this week, I will need to remember that I can’t just step onto the road if I’m walking along the footpath on the right-hand side. In the UK and Australia, where we drive the correct side, it’s fine (just don’t tell my kids), because the cars that are nearest me are coming towards me – except of course, the ...

This month’s T-SQL Tuesday has me caught slightly unawares. I’m in the UK, having come over for SQLBits, and I’m left writing this with only a few hours to go. The theme this time is on misconceptions in SQL, and this fits nicely with SARGability – one of the topics that I presented on at SQLBits a week and a half ago. I often see people refer ...

No really – hear me out. Of course you create tables, and you query tables, and we say that data is stored in tables. The table is (rightly) a fundamental part of relational theory. But I find that when I think about queries and how they run, I need to approach the system thinking about the indexes that I’m querying, not the tables. When you ...

We have just two weeks to go before Paul Randal and Kimberly Tripp touch down in the Boston area to deliver their famous SQL Server Immersions course. This is going to be a truly fantastic SQL Server learning experience and we're hoping a few more people will join in the fun. This is where you come in: we have a few vacant seats remaining and we ...

(Reposted from my msmvps.com blog) A recent discussion on Twitter about a query that Denny Cherry was looking at led to this post by Josef Richberg: http://josef-richberg.squarespace.com/journal/2010/1/28/is-a-case-statement-considered-sargable.html, and I thought it might be worth going through a few points on the topic of SARGability. ...

If you've been looking for advanced training in the northeast, your wait is over. Paul and Kimberly will be gracing us with one of their famous ''SQL Server Immersion'' events the week of March 29. This course will cover storage engine internals, indexing and performance strategies, and of course in-depth sections on database maintenance from the ...

(Reposted from my msmvps.com blog) SARGable is an adjective in SQL that means that an item can be found using an index (assuming one exists). Understanding SARGability can really impact your ability to have well-performing queries. Incidentally – SARGable is short for Search ARGument Able. If you have an index on phone numbers using LastName, ...

Usually, we think of index seeks (a possible Query Execution Plan operation) as using the b-tree index to pick out a row and then quickly pass that row to the next operation. But the index seek has special powers: when the conditions are right, it can examine non-key columns and filter based on those values inside the index seek operation. When ...

I asked for some names of people who you would like to see interviewed and Craig Freedman's name popped up a couple of times. I contacted Craig and he was kind enough to take time out from his busy schedule to answer these questions.  So, here are the questions. What are the most important things a person can do to master SQL ...

In the first post of this series, I explained the bin-packing problem and established a baseline solution. The second post investigated ways to increase the packing efficiency. In none of these posts did I pay particular attention to performance – and frankly, it shows. Performance of all solutions presented thus far sucks eggs. Time to see what ...