Archive for February, 2011

Call me Ishmael

This week I’ve been chasing my own white whale.  Another developer came to me with this little problem.  A query he was trying to run over a linked server to an Oracle database was returning unexpected results.  Here’s his original query: select count(order_num) from openquery(PROD, ‘select t2.order_num from myschema.mytable t2 where open_date < to_date(”01-JAN-2011”, ”DD-MON-YYYY”) [...]

February 25, 2011  Tags: , , , , ,   Posted in: Troubleshooting  No Comments

Heisenbug

From Wikipedia: A heisenbug (named after the Heisenberg Uncertainty Principle) is a computer bug that disappears or alters its characteristics when an attempt is made to study it. Yep, sounds about right. The timeout problem has not happened once since I put monitoring into place on Monday morning.

February 18, 2011  Tags: ,   Posted in: Troubleshooting  No Comments

The waiting is the hardest part

A developer came to me last week with a problem.  A relatively simple query within his application that normally takes under a second to run, is intermittently taking upwards of 30 seconds.  This, in turn, is causing his application to time out.  He said he could increase the timeout on his application to work around [...]

February 15, 2011  Tags: ,   Posted in: Troubleshooting  2 Comments

Plan guides and parameterization

We’ve all had this experience. A third party application is running a piece of sql that simply isn’t choosing the best query plan, and if only it would use a hash join instead of a nested loop. Or maybe it’s blocking other processes and a nolock hint would help. The problem is, you can’t change [...]

February 9, 2011  Tags: , ,   Posted in: SQL Tuning, T-SQL  No Comments

The obligatory first post

This past weekend I attended SQL Saturday here in sunny Cleveland.  And while there were probably more fun ways to spend a Saturday, I have to say I’m very glad I went.  There were some great sessions by Steve Jones, Thomas LaRock, Grant Fritchey, and Jeremiah Peschka and I learned a ton of information. However, [...]

February 8, 2011  Tags: , ,   Posted in: Professional Development  No Comments