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)
43,056 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)
27,759 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)
41,699 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
8,757 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)
218,964 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)
26,775 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)
141,487 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
20,153 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)
44,333 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)
65,065 reads
By DataOnWheels
I have been active in the data community throughout my career. I have met...
By Vinay Thakur
Quick Summary for Microsoft SQL Server till 2025, I am fortunate to be part...
By James Serra
Why this comparison feels confusing If you’re a Power BI report author who’s just...
I have mentioned this several times over several years. Can someone please help me...
SELECT COUNT(DISTINCT Component) AS Found FROM tblComponents WHERE(Component NOT LIKE '%[a-z]%') AND(LTRIM(RTRIM(Component)) = 'GM13622')...
Comments posted to this topic are about the item Remotely Engineer Fabric Lakehouse objects:...
In a SQL Server 2025 table, called Beer, I have this data:
BeerIDBeerName 1Becks 2Fat Tire 3Mac n Jacks 4Alaskan Amber 8KirinI run this code:
SELECT JSON_OBJECTAGG(
BeerID: BeerName )
FROM beer;
What are the results? See possible answers