Data Warehouse Considerations - SCD Type 2 vs Overwrite Dimension Tables
How we handle data warehousing updates to dimension tables is crucial and this article covers Slowly Changing Dimensions versus overwriting tables.
2024-12-20
How we handle data warehousing updates to dimension tables is crucial and this article covers Slowly Changing Dimensions versus overwriting tables.
2024-12-20
How much load do real time updates place on a data warehouse? Steve has a few thoughts on the analysis of the Amazon Redshift dataset, Redset.
2024-10-07
151 reads
Learn how you can model days in a dimension that might need to be aggregated in different ways for your data warehouse operations.
2024-02-07
1,937 reads
This article gives an overview of Amazon Redshift, the cloud data warehouse in AWS.
2023-07-24
25,508 reads
In 2019 Canadian Broadcasting Corporation (CBC) news reported a massive data breach at the Desjardins Group, which is a Canadian financial service cooperative and the largest federation of credit unions in North America. The report indicated, a "malicious" employee copied sensitive personal information collected by Desjardins from their data warehouse. The data breach compromised the […]
2022-03-30
3,071 reads
Agile data warehousing can be challenging. Pairing the right methodologies and tools can help. Here is how my team met the challenge by using Data Vault methodology and BIML scripting.
2014-09-04
2,592 reads
2014-07-24
1,633 reads
In this article, Arshad Ali goes intp detail about how a data warehouse is different from operational data store and the different design methodologies for a data warehouse.
2013-07-03
6,374 reads
A primer on how to reduce network and source system load when reading a relational source into the data warehouse.
2012-07-30
5,493 reads
SQL Server 2008 introduced many new functional and performance improvements for data warehousing, and SQL Server 2008 R2 includes all these and more. This paper discusses how to use SQL Server 2008 R2 to get great performance as your data warehouse scales up. We present lessons learned during extensive internal data warehouse testing on a 64-core HP Integrity Superdome during the development of the SQL Server 2008 release, and via production experience with large-scale SQL Server customers. Our testing indicates that many customers can expect their performance to nearly double on the same hardware they are currently using, merely by upgrading to SQL Server 2008 R2 from SQL Server 2005 or earlier, and compressing their fact tables. We cover techniques to improve manageability and performance at high-scale, encompassing data loading (extract, transform, load), query processing, partitioning, index maintenance, indexed view (aggregate) management, and backup and restore.
2011-05-19
5,175 reads
By Rayis Imayev
(2025-Feb-12) I will jump straight to the problem statement without a "boring" introduction, which, in...
By Steve Jones
I wrote about getting the Redgate Test Data Manager set up in 10 minutes...
I wrote a stream-of-consciousness post a few months ago about what I do in...
I'm a retired IT guy in his 80s fighting boredom by trying to learn...
I just joined and posted a brief profile. This is my first post. Please...
WHERE a.ROWID IN (SELECT rid FROM ( SELECT ROWID rid, row_number() OVER (PARTITION BY...
I have this table and data:
CREATE TABLE [dbo].[SalesTracking] ( [SalesDate] [datetime] NULL, [SalesPersonID] [int] NULL, [CustomerID] [int] NOT NULL, [PONumber] [varchar] (80) COLLATE SQL_Latin1_General_CP1_CI_AS NULL, [paid] [bit] NULL, [total] int ) ON [PRIMARY] GO CREATE CLUSTERED INDEX [SalesTrackingCDX] ON [dbo].[SalesTracking] ([SalesDate]) ON [PRIMARY] GO INSERT dbo.SalesTracking (SalesDate, SalesPersonID, CustomerID, PONumber, paid, total) VALUES ('2024-03-15 10:45:55.067', 1, 1,'PO965' ,1, 100), ('2023-09-24 10:45:55.067', 1, 2,'PO627' ,1, 200), ('2022-07-02 10:45:55.067', 1, 3,'PO6' ,1, 300), ('2022-11-03 10:45:55.067', 1, 4,'PO283' ,1, 400), ('2022-11-26 10:45:55.067', 1, 5,'PO735' ,1, 500), ('2023-04-28 10:45:55.067', 1, 6,'PO407' ,1, 600), ('2022-09-09 10:45:55.067', 1, 7,'PO484' ,1, 700), ('2024-03-13 10:45:55.067', 1, 8,'PO344' ,1, 700), ('2024-04-24 10:45:55.067', 1, 9,'PO254' ,1, 800), ('2022-06-19 10:45:55.067', 1, 10,'PO344',1, 800) GOWhen I run this query, how many unique values are returned for the SalesRank column?
SELECT st.SalesDate , st.SalesPersonID , st.total , RANK () OVER (PARTITION BY st.SalesPersonID ORDER BY st.total desc) AS SaleRank FROM dbo.SalesTracking AS st;See possible answers