A fresh statistic can still come from a small sample. Compare rows with rows_sampled and see how a sample misjudges a rare value.
Forwarded Records and Performance – SQL in Sixty Seconds #155
Forwarded records make SQL Server read extra pages when it scans a heap. In this SQL in Sixty Seconds video, I explain forwarded records and performance.
SQL SERVER – Finding Fragmentation in Forwarded Records
Finding Fragmentation in a heap also requires a separate check for forwarded records. I measure their effect before choosing maintenance.
Instance Level Fill Factor or Index Level: What to Set
An instance level fill factor is a default for every index that sets none, and an index level setting wins. This post reads the setting, measures what each fill factor costs in pages and saves in page splits, and gives a plan for choosing the level.
Uniquifier: The Hidden Cost of Duplicate Clustered Keys
The uniquifier is a hidden 4-byte value that SQL Server adds to duplicate keys in a non-unique clustered index. This post measures its real cost row by row on SQL Server 2025 and shows it on the page. It also compares it with a unique key you choose yourself.
Logging Free Space per Volume Into a Table Each Day
Log free space per volume from SQL Server volume metadata, keep one daily sample per mount point, and compare change with LAG.
Can a Database Have Multiple Files with Extension MDF? – Interview Question of the Week #279
Question: Can a Database Have Multiple Files with Extension MDF?
Answer: Yes. It is possible to have multiple files with extension MDF.