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Sometimes the Simplest Solution Isn't the Best Solution (The All-In-One Search Query)

Programmers should naturally gravitate toward the simplest, most elegant solution. This is because the simplest coding solution is so often the best solution: simple solutions are cheaper to implement; easier for others to understand, maintain, and extend; Read More...
Posted Sunday, May 03, 2009 8:13 PM by bartd | 11 Comments

Query Fingerprints and Plan Fingerprints (The Best SQL 2008 Feature That You've Never Heard Of)

In versions of SQL Server before SQL Server 2008, it can be difficult to determine the cumulative cost of the queries running on a server if the workload includes unparameterized queries. The only truly reliable method is to capture a Profiler trace during Read More...
Posted Wednesday, September 03, 2008 8:20 PM by bartd | 2 Comments
Attachment(s): fingerprint_screenshot_2.png

Joins Dissected on CraigFr's blog

CraigFr has a great series of posts in his blog describing the difference between the various logical and physical join types, the details of how SQL Server implements these joins, and the things that the query optimizer takes into account when selecting Read More...
Posted Wednesday, August 16, 2006 8:13 PM by bartd | 0 Comments

SELECT from a view slower than "equivalent" SELECT from the base table

Sometime we get complaints that a query is slower than it could be because a filter isn’t pushed very deeply down into a plan. For example, consider this hypothetical poor performance scenario (my apologies in advance for the lack of normalization): USE Read More...
Posted Monday, August 14, 2006 11:39 PM by bartd | 4 Comments
Attachment(s): like_views_nopush.sql

Wide vs. Narrow Plans

Here's another case where you might see intermittently poor performance that is "by design". Suppose you see that a delete, insert, or update query in a stored proc usually runs quickly, but occasionally the query takes much longer to complete. You captured Read More...
Posted Thursday, July 27, 2006 6:29 PM by bartd | 5 Comments

Limited Statistics Granularity

To set up this scenario, run the script below: USE tempdb GO IF OBJECT_ID ('test1') IS NOT NULL DROP TABLE test1 GO CREATE TABLE test1 (c1 tinyint, c2 smallint) DECLARE @x int DECLARE @msg varchar(1000) SET @x = 1 SET NOCOUNT ON BEGIN TRAN WHILE (@x <= Read More...
Posted Tuesday, July 25, 2006 5:37 PM by bartd | 8 Comments

Why a bad plan isn't necessarily a bug

Everyone that has worked with databases for long enough has run into situations where the query optimizer doesn't select the best possible plan. You may find that you can force SQL to use an index, choose a different join algorithm or join order, or use Read More...
Posted Tuesday, July 25, 2006 4:54 PM by bartd | 0 Comments
Attachment(s): pbm_health_create.png
 
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