Tag: Hashing

SQL

Retrofitting Schemas with Computed Columns

Post author By Andy B.
Post date Aug 4, 2026
2 Comments on Retrofitting Schemas with Computed Columns

Computed columns allow us to bake logic into our schema. I find particular use for these when reviewing or optimising established solutions where you spot the quirky ways the data is being used. Here I want to demonstrate 3 symptoms and show how different implementations of computed columns solve them. Baking the expression Common expressions […]

Tags Computed Columns, Expressions, Hashing, Optimisation, Performance, Persisted, Querying, Tuning

T-SQL Tuesday

T-SQL Tuesday #198 – Change Detection

Post author By Andy B.
Post date May 12, 2026
2 Comments on T-SQL Tuesday #198 – Change Detection

Being a Data Engineer, this month’s invitation from Meagan resonates. She’s asked us to share a tip, technique, or lesson about detecting changes – which can be crucial to reduce workload across a large dataset. I’ll rewind back a number of years to an overnight batch process which ingested key transactional data for a business. Due to […]

Tags Change Detection, Hashing, Optimisation, Performance, Performance Tuning, T-SQL Tuesday