Why CQRS and Event Sourcing Are Gaining Ground in High-Concurrency Web Systems

In web app development company boardrooms, architects and engineers are debating old assumptions. Scaling up isn’t just about faster servers or better caching anymore. It’s about reshaping how systems think. CQRS (Command Query Responsibility Segregation) and Event Sourcing are no longer fringe ideas. They’re becoming default choices in high-concurrency systems where consistency, auditability, and performance […]

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Working with Indexes on SSMS

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Yet another Date Dimension

Evolution of code The thing with any bit of code that has been around for a while, is that when change comes along, the tendency is to cater for the change by adding new stuff, while nothing gets taken away.  Some stuff has  definitely been taken away from this Date Dimension, but some historical artefacts […]

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Add a Second NIC for an Availability Group to Separate Network Traffic

Introduction Sometimes we face the scenario in an enterprise environment that the database in SQL Server Always On Availability Group (AOAG) has high concurrency read and write access from application servers. If we keep using the one network interface card for both network traffic of database connections from application servers and database mirroring between AOAG […]

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Picking the ON or WHERE Clause for the SQL Predicate

Helping people solve T-SQL problems is one of my favorite hobbies. Someone messaged me the other day with a complex query that was almost complete except for one issue. He needed to perform a LEFT OUTER JOIN but had to filter based on a value from the right table. However, when he added the filter, SQL removed rows from the left table. The task was to decide where to place the SQL predicate: in the ON or WHERE clause.

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Question of the Day

Getting the Average

I have this data in the dbo.Commission table in a SQL Server 2022 database. 

salesperson commission
Brian       12
Brian       16
Andy        7
Andy        14
Andy        21
Steve       20
Steve       NULL
All the data is a varchar, and I decide to run this query to get the totals for each salesperson. 
SELECT SalesPerson
     , AVG(TRY_PARSE(Commission AS int)) AS TotalCommission
 FROM commission
 GROUP BY SalesPerson
GO
What average commission is calculated for Steve?

See possible answers