Kevin Griffin personal blog

C# strings silently kill your SQL Server indexes in Dapper

by @1kevgriff consultwithgriff.com published 2026-03-057 min read

If you're using Dapper with anonymous objects to query varchar columns, you're probably sending nvarchar(4000) parameters — causing CONVERT_IMPLICIT on every row and defeating your indexes. Here's the fix.

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Databases & DataSoftware Engineering2026

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