Introduction This article celebrates a classic algorithm [1] of Dijkstra (1930 – 2002) which finds a path of minimal cost between any pair of nodes in an undirected graph. His procedure is widely recognized as a fundamental tool for examining communication and transportation networks (eg. Google Maps) and is surprisingly simple. By his own admission, […]
2024-01-05
7,151 reads
Introduction The sp_HorizontalTree procedure introduced here may be used to audit tables with dependent columns. A column is dependent on another if the meaning of the first column depends on the meaning of the second. For example, in a table containing accounting information, the meaning of a Fiscal Quarter column depends on the Fiscal Year to […]
2023-06-16
2,321 reads
Introduction This article shows how to script a basic merge between two tables, without using MERGE. This can be handy when you're merging a pair of tables with hundreds of columns, since the script doesn't know anything about them. This technique introduces and populates some auditing columns (IS_DELETED, IS_INSERTED, IS_UPDATED, TRANSACTION_DATE) for each record, and runs fast. […]
2023-02-20 (first published: 2020-04-14)
18,243 reads
In this article, Glen Cooper provides code that allows you to process a tree, or undirected graph of data. Lots of hierarchies fall into this category and the ability to process them is valuable in many reporting situations.
2023-01-20
3,195 reads
Learn a little basic graph theory in this article that replaces a GROUP BY clause.
2022-07-04 (first published: 2019-10-17)
11,742 reads
This article presents a way that finds a perfect match in any bipartite graph or shows why one cannot exist.
2021-09-06
2,799 reads
Introduction This article shows how common table expressions (CTE) in SQL Server are naturally suited for navigating trees, such as finding its longest path, or diameter. Recall that a tree is an undirected graph where unique paths exist between any two nodes (i.e. vertices). Any node may be selected as its top node, with its […]
2021-04-19
7,359 reads
This article shows how to solve a gaps and islands problem using simple algebra.
2020-03-10
4,925 reads
In this article, we see how SQL can be used to determine matches between two groups, given a set of preferences.
2020-01-23
7,048 reads
An interesting tutorial for linking SQL Server to a Blackberry device and viewing images.
2011-02-09
11,411 reads
By Brian Kelley
The bottom line here is this: the idea that a CSP takes care of...
In today's data-driven world, SQL (Structured Query Language) is a blazing-hot skill. It's your...
By Steve Jones
I leave tonight for Australia. I was in London 3 days ago, so this...
I have been asked to fine-tune the following SQL that was written by a...
In this scenario, I seek assistance in implementing row-level permissions for a table named...
I've tried different credentials, target server versions, etc. hitting our Primavera WSDL. Works great...
What are the initial config sizes for the tempdb primary data files, secondary data files, and log files in SQL Server 2022?
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