2017-09-22
1,141 reads
T-SQL
2017-09-21
932 reads
2017-09-18
1,174 reads
2017-09-12
1,033 reads
SQL Data Aggregation Aggravation
When we have to deal with and store a lot of data, it makes sense to aggregate it so that we store only the information we actually need. If we get this right, this works well, but the design of the system takes care and thought because the problems can be subtle and various. Joe Celko describes some of the ways that things can go wrong and end up providing incorrect, inaccurate or misleading results.
2017-09-12
3,866 reads
2017-09-05
1,105 reads
Statistics in SQL: The Mann–Whitney U test
Phil Factor shows how to use the Mann-Whitney U test in SQL to to find out whether two samples come from the same distribution.
2017-09-04
4,456 reads
2017-08-31
1,152 reads
2017-08-22
1,202 reads
Statistics in SQL: The Kruskal–Wallis Test
Before you report your conclusions about your data, have you checked whether your 'actionable' figures occurred by chance? The Kruskal-Wallis test is a safe way of determining whether samples come from the same population, because it is simple and doesn't rely on a normal distribution in the population. This allows you a measure of confidence that your results are 'significant'. Phil Factor explains how to do it.
2017-07-27
6,123 reads
Blogs
Advice I Like: Respect
By Steve Jones
“Don’t aim to have others like you; aim to have them respect you.” –...
Blue Sky Programming – The Optimism Trap
Many years ago, before I joined Oracle, I was working on a major modernisation...
Setting Up a Mac for Data Engineering and AI Work
If you work with data pipelines, SQL, notebooks, or machine learning models, a Mac...
Forums
SQL Art, Part 4: Happy 4th of July — A British DBA's Guide to Celebrating a War We Don't Talk About
Comments posted to this topic are about the item SQL Art, Part 4: Happy...
locking down agent for new user on our dev machine
hi , a new user wants to be able to add sql agent jobs...
SQL Server Enum Implementation: A Single-Row View Strategy for Avoiding Magic Values
Comments posted to this topic are about the item SQL Server Enum Implementation: A...
Question of the Day
BIT_COUNT I
In SQL Server 2025, I have a table (dbo.UserPermission) that contains this data:
UserID UserPermissions 15 23 37What is returned when I run this code:
select bit_count(UserPermissions) as PermissionCount from dbo.UserPermission where UserID = 3;See possible answers