Hash Joins on Nullable Columns
Paul White explores some less well-known query optimizer features and limitations, and explains the reasons for extremely poor hash join performance in a specific case.
2015-11-16
3,593 reads
Additional Articles
Capture Execution Plan Warnings using Extended Events
Erin Stellato of SQLskills shows how to use Extended Events to monitor for query plans with certain characteristics, such as joins missing predicates, columns missing statistics, and unmatched filtered indexes.
2015-11-13
2,571 reads
Automating Your SQL Server Best Practice Reports: The Document
If you're making a report from table-based data, an MS Word document is often a good option. In the second part of his introduction to SQL Server best-practice monitoring, Laerte Junior shows how to use PowerShell scripts to create a Word-based report with colour-coded alerts where there are problems or best practices aren't being followed.
2015-11-12
8,610 reads
Extended Statistics and Oracle 12c
David Fitzjarrell looks at how and why to use a feature called Automatic Column Group Detection to recognize column dependencies and create extended statistics on recognized groups in Oracle 12.1.0.2.
2015-11-11
3,177 reads
Introduction to PolyBase in SQL Server 2016 - Part 1
One of the features introduced in SQL Server 2016 is PolyBase. The goal of PolyBase is to make interacting with unstructured, semi-structured and non-relational data stored in Hadoop as easy as writing Transact-SQL statements. Edwin Sarmiento explains.
2015-11-10
3,022 reads
Implementing Continuous Integration for Databases
Continuous integration (CI) is becoming more and more common in application development. It ensures code and related resources are integrated regularly and tested by an automated build system, and highlights problems early in the development process. But what about database development? Can the same advantages of CI be applied to production databases? Where do you start? How do you tackle it? Sjors Takes relates his experience.
2015-11-09
2,651 reads
How to Create Ten 200GB Test Databases in 60 Seconds
In a recent survey run SQL Server Central, 58% of respondents admitted that their test database is an exact copy of their production database. Many of these respondents concede that they should be removing sensitive data, but aren’t. It seems that the desire to have realistic data will, for many, trump the requirement to keep sensitive data out of development and test environments. In this blog post, Redgate's Jason Crease introduces the new 'SQL Instant Clone' and explains how it could help.
2015-11-06
4,497 reads
Knee-Jerk Wait Statistics : PAGELATCH
Paul Randal adds another chapter to his thorough series on knee-jerk wait statistics, focusing on the often-misunderstood PAGELATCH_XX waits.
2015-11-05
5,574 reads
SQL Server Reporting Services General Best Practices
Ghanesh Prasad discusses 12 best practices any developer or DBA should follow when working on a SSRS project.
2015-11-04
5,092 reads
So You Need to Expose JSON Endpoints
Even the most experienced programmers can be caught out unawares by software they've used for years without trouble. Dino Esposito explains why and how the JSON method in an ASP.NET MVC controller class suddenly started to cause an exception on a production server, and how he fixed the problem.
2015-11-03
2,813 reads
Blogs
RANK() vs DENSE_RANK(): #SQLNewBlogger
By Steve Jones
I haven’t done one of these in awhile, but I saw an article recently...
Using CAT for Testing of Data Agents
In last months one of the scenarios where you can use AI has been...
Are you getting value from your reporting?
By ChrisJenkins
Do you spend so long manipulating your data into something vaguely useful that you...
Forums
Creating JSON II
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Question of the Day
Creating JSON II
On SQL Server 2025, what happens when I run this code:
SELECT JSON_OBJECTAGG( N'City':N'Denver' RETURNING JSON) GOSee possible answers