SQL Server MVP Jeff Moden shows us a new very high performance method to convert an "Adjacency List" to “Nested Sets” on a million node hierarchy in less than a minute and 100,000 nodes in just seconds. Not surprisingly, the "steroids" come in a bottle labeled "Tally Table".
2014-09-19 (first published: 2012-11-13)
43,021 reads
It's a well known fact that Scalar UDFs are the stuff of performance nightmares in T-SQL. But are they really as bad as they say? SQL Server MVP Jeff Moden shows us that they might not really be as big a problem as you might think and what you can do when they actually are.
2014-06-24 (first published: 2012-08-01)
27,749 reads
A simple problem that can become complex in T-SQL. How do you find the rows that match 2 conditions, but not a third, in an efficient manner. MVP Jeff Moden gives us a solution.
2014-06-06 (first published: 2012-03-29)
41,695 reads
SQL Server MVP Jeff Moden walks us through the classic problem of finding all the "Active" rows for the previous month using start and end dates. This is excellent for those new to T-SQL.
2014-01-30
8,756 reads
Get correct answers to your SQL forum questions faster by making it easier to load your sample data and read your code.
2013-12-10 (first published: 2007-11-27)
218,887 reads
Another in the series of articles to help you "fill in the cracks" in your T-SQL knowledge. MVP Jeff Moden shows us a super simple, high performance method to solve this timeless problem.
2013-07-19 (first published: 2011-01-20)
26,754 reads
The Tally Table has proven to be a simple and elegant method for avoiding many varieties of RBAR. Unfortunately, one of its more common uses, that of a CSV splitter, has a well-known and serious performance problem. MVP Jeff Moden shows us what that problem is and how to correct it. (UPDATED with additional info and attachments on 5/12/2011).
2012-12-28 (first published: 2011-05-02)
141,424 reads
In this sequel to his first "Hierarchies on Steroids" article, SQL Server MVP Jeff Moden shows us how to build a pre-aggregated table that will answer most of the questions that you could ask of a typical hierarchy. Any bets on whether Santa is packin’ a Tally Table in his bag or not?
2012-11-15
20,148 reads
Another in our series of articles to help you fill in the cracks in your knowledge with SQL Spackle. MVP Jeff Moden shows us how IsNumeric works and how you should use it.
2012-09-14 (first published: 2010-12-01)
44,318 reads
Replacing multiple spaces with a single space is an old problem that people use loops, functions, and/or Tally tables for. Here's a set based method from MVP Jeff Moden.
2012-08-17 (first published: 2009-11-16)
65,051 reads
In last months one of the scenarios where you can use AI has been...
By ChrisJenkins
Do you spend so long manipulating your data into something vaguely useful that you...
By Steve Jones
It was neat to stumble on this in the book, a piece by me,...
Comments posted to this topic are about the item Creating JSON II
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On SQL Server 2025, what happens when I run this code:
SELECT JSON_OBJECTAGG( N'City':N'Denver' RETURNING JSON) GOSee possible answers