Bert Wagner

Bert Wagner is a Business Intelligence Developer at Progressive Insurance. He enjoys solving challenging data transformations with T-SQL and optimizing for query performance. In addition to BI development, Bert loves building ASP.NET MVC web apps and building Internet of Things projects.

Blog Post

Correlated Subqueries vs Derived Tables

Correlated subqueries provide an intuitive syntax for writing queries that return related data. However, they often perform poorly due to needing to execute once for every value they join on....

2019-05-07 (first published: )

1,718 reads

Blog Post

Temporary Staging Tables

Watch this week’s episode on YouTube. SQL Server Spool operators are a mixed bag. On one hand, they can negatively impact performance when writing data to disk in tempdb....

2019-05-07

234 reads

Blog Post

Temporary Staging Tables

Watch this week's video on YouTube
SQL Server Spool operators are a mixed bag. On one hand, they can negatively impact performance when writing data to disk in tempdb. On...

2019-05-07

4 reads

Blog Post

Temporary Staging Tables

Watch this week's video on YouTube
SQL Server Spool operators are a mixed bag. On one hand, they can negatively impact performance when writing data to disk in tempdb. On...

2019-05-07

5 reads

Blog Post

IN vs UNION ALL

Watch this week's video on YouTube
When you need to filter query results on multiple values, you probably use an IN() statement or multiple predicates separated by ORs:
WHERE Col1 IN...

2019-04-30

2 reads

Blog Post

IN vs UNION ALL

Watch this week's video on YouTube
When you need to filter query results on multiple values, you probably use an IN() statement or multiple predicates separated by ORs:
WHERE Col1 IN...

2019-04-30

11 reads

Blog Post

Window Functions vs GROUP BYs

There are many options available for improving the performance of a query: indexes, statistics, configuration settings, etc… However, not all environments allow you to use those features (eg. vendor...

2019-04-25 (first published: )

1,240 reads

Blogs

T-SQL Tuesday #192 Invitation: SQL Server 2025 Excitement

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It’s that time of the month again, and once again, I’m late and I’m...

The Book of Redgate: What Our Customers Say

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This is from 2010, but I loved that people felt this way about Redgate...

Export a Power BI Report that cannot be Downloaded

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Yes, you’re reading that right, we’re going to download a report that cannot be...

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Forums

Economics of AI: What is the Real Cost to Profit?

By dbakevlar

Comments posted to this topic are about the item Economics of AI: What is...

Poor Name Choice

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Poor Name Choice

Getting the Indexed Columns

By Steve Jones - SSC Editor

Comments posted to this topic are about the item Getting the Indexed Columns

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Question of the Day

Getting the Indexed Columns

I run this code on SQL Server 2022 to get a list of all the indexes and their key columns. What is returned?

SELECT   
    INDEX_COL (N'AdventureWorks2017.Sales.SalesOrderDetail')

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