Tips, Tricks, and Advice from the SQL Server Query Processing Team
The query processing team - query optimization & execution - providing tips, tricks, advice and answers to freqeuently-asked questions in a continued effort to make your queries run faster and smoother in SQL Server.
If you examine Showplan XML, you may find an entry like <MemoryFractions Input="1" Output="1"...
Date: 03/11/2010
This article describes how query memory grant works in Microsoft SQL Server. It applies to both...
Date: 02/16/2010
SQL Server's server cursor model is a critical tool to many application writers. Fast_forward...
Date: 08/12/2009
Distinct aggregation (e.g. select count(distinct key) …) is a SQL language feature that results in...
Date: 09/22/2008
Since SQL Server 2005, query plan as well as statistics of query execution can be captured in XML...
Date: 06/01/2007
Index Build strategy in SQL Server - Part 4-2: Offline Serial/Parallel Partitioning (Non-aligned partitioned index build)
Source PartitionedWhile the table is partitioned, we may want to change the way it is partitioned...
Date: 05/14/2007
Index Build strategy in SQL Server - Part 4-1: Offline Serial/Parallel Partitioning (Non-aligned partitioned index build)
Recall that in the previous posts on index build, we defined "aligned" as the case when base object...
Date: 05/08/2007
The star join optimization technique is an index based optimization designed for data warehousing...
Date: 04/09/2007
One of the less well-known warning events that is logged to SQL Profiler trace is the Hash Warning...
Date: 02/01/2007
Index Build strategy in SQL Server - Part 3: Offline Serial/Parallel Partitioning (Aligned partitioned parallel index build)
Aligned partitioned parallel index build In case of parallel build we scan and sort partitions in...
Date: 01/19/2007
There are two main categories of partitioned index build: Aligned (when base object and in-build...
Date: 01/16/2007
Index Build strategy in SQL Server - Part 2: Offline, Parallel, No Partitioning (Non stats plan (no histogram))
Build (serial) (write data to the in-build index) | X (Merge exchange) / | \ Sort… Sort… Sort...
Date: 12/13/2006
The type of parallel index build plan in SQL server depends on whether or not we have a histogram...
Date: 12/11/2006
Checklist for time out errors Memory pressure: In most cases timeouts are caused by insufficient...
Date: 11/22/2006
Builder (write data to the in-build index) | Sort (order by index key) | Scan (read data from...
Date: 11/20/2006
This short article provides a checklist for query execution time out errors in Yukon. It does not...
Date: 11/14/2006
ETW stands for “Event Tracing for Windows” and it is used by many Windows applications to provide...
Date: 11/12/2006
- Building Partitioned Index vs. Building non-Partitioned Index: The data of partitioned tables and...
Date: 11/09/2006
Index Build strategy in SQL Server may vary depending on users needs. Each of these Index Build...
Date: 11/08/2006
One of the least understood Query Execution operators is the Bitmap. I'd like to give a fairly brief...
Date: 10/27/2006
Statistics profile output is an important tool when it comes to troubleshooting query plan issues....
Date: 10/20/2006
Besides SSMS, another great tool available to database developers and DBAs to view query plans and...
Date: 10/17/2006
As mentioned in our previous blog posting, SQL Server 2005 supports Showplan generation in XML...
Date: 10/06/2006
Showplan is a feature in SQL Server to display and read query plans. While some of you may already...
Date: 09/29/2006
I've helped a lot of people upgrade their SQL 2000 applications to SQL 2005. While many of these...
Date: 09/27/2006
Since we’re starting a new blog for the whole query processing team, we think it’s appropriate to...
Date: 09/25/2006
This blog will serve as the new spot for content from the SQL Server Query Processor team. The old...
Date: 09/20/2006