Technical Article

Understanding and Controlling Parallel Query Processing in SQL Server

Data warehousing and general reporting applications tend to be CPU intensive because they need to read and process a large number of rows. To facilitate quick data processing for queries that touch a large amount of data, Microsoft SQL Server exploits the power of multiple logical processors to provide parallel query processing operations such as parallel scans. Through extensive testing, we have learned that, for most large queries that are executed in a parallel fashion, SQL Server can deliver linear or nearly linear response time speedup as the number of logical processors increases. However, some queries in high parallelism scenarios perform suboptimally. There are also some parallelism issues that can occur in a multi-user parallel query workload. This white paper describes parallel performance problems you might encounter when you run such queries and workloads, and it explains why these issues occur. In addition, it presents how data warehouse developers can detect these issues, and how they can work around them or mitigate them.

Blogs

Finally Cleaning Up Dropbox: Moving Almost a TB to Google Drive with rclone

By

I’ve had a Dropbox account for years. Like a lot of people, I started...

KDA: Echoes of Deception - Case 4

By

Someone hacked Digitown's municipality and stole classified documents. 45 million rows of router traffic,...

EightKB 2026 – Schedule and Registration

By

Hello Hello, We. Are. Back! The schedule for EightKB 2026 Edition has been announced!...

Read the latest Blogs

Forums

identity increments by 10,000 when it was supposed to be 1

By stan

hi a peer of mine who ive never known to be wrong says a...

Displaying Money

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Displaying Money

The Slow Growing Problems

By Steve Jones - SSC Editor

Comments posted to this topic are about the item The Slow Growing Problems

Visit the forum

Question of the Day

Displaying Money

I want to get the currency sign displayed with my amount stored in a money type. Does this work?

DECLARE @Amount MONEY;
SET @Amount = '?1500';

SELECT CAST( @Amount  AS VARCHAR(30)) AS Euros

See possible answers