A heap in SQL Server is a table with no clustered index. Forwarded records pushed one count from 11,113 reads to 199,844, and a single REBUILD put it back. When a heap is fine and when it is not.
Silent Truncation When Building Strings in nvarchar(max) Variables
Silent truncation can happen while SQL Server evaluates a bounded expression. These examples compare the lost characters with a max expression and a max REPLICATE input. Check stored lengths before blaming a clipped display.