CHECKDB’s Hidden Snapshot

I am in the middle of some research regarding CHECKDB and learnt something new. From SQL Server 2014 onwards the database snapshot that is used to get to a transactionally-consistent point-in-time is no longer hidden.

To understand the behavior prior to 2014 I am going to quote Paul Randal here – he states “ As the database snapshot is hidden, there is no control over where the snapshot files are placed – in fact they are created as alternate streams of the files comprising the source database” (http://www.sqlskills.com/blogs/paul/checkdb-from-every-angle-complete-description-of-all-checkdb-stages/)

In SQL Server 2014 things have changed – it is not hidden and it doesn’t use alternate streams.

DBCC CHECKDB ('Newdb')

Checking the location where the data files reside we can see the snapshot.

checkme.JPG

This disappears once CHECKDB finishes.

 

One thought on “CHECKDB’s Hidden Snapshot

  1. Pingback: CHECKDB Snapshots – Curated SQL

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