Posts

Showing posts with the label Performance

Deadlocks of an Azure Database

If your Azure database is experiencing deadlocks or below error Transaction (Process ID) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction then you can see them by executing following query in the master database:

Assigning values to variables from same table but different rows

Image
I often see developers assigning values to variables from the same table but different rows based on the row ID. The values are mostly from the same column. What I see is the table is queries multiple times and could impact performance. Below is the sample query and its execution plan. DECLARE @Method1 nvarchar(50); DECLARE @Method2 nvarchar(50); SET @Method1=(SELECT DeliveryMethodName FROM [Application].[DeliveryMethods] WHERE DeliveryMethodID=1); SET @Method2=(SELECT DeliveryMethodName FROM [Application].[DeliveryMethods] WHERE DeliveryMethodID=2); Instead, we can do it as in below query: This can also be used while fetching values from an XML column or variable based on a node.

Make Money from Surveys