The ToSql instance for Text can generate very large expressions of + which throws the following error on my installation of SQL Server.

Internal error: Server stack limit has been reached. Please look for potentially deep nesting in your query, and try to simplify it.

The use-case that caused us to hit this was a modestly-sized HTML document, but here's a more minimal example:

blowup cn = query cn ("select " <> toSql (Data.Text.replicate 2000 ">"))