DBCC Extended Checks

The SQL Server CSS team has a new post on DBCC performance improvements:

Starting with SQL Server 2016, additional checks on filtered indexes, persisted computed columns, and UDT columns will not be run by default to avoid the expensive expression evaluation(s.)  This change greatly reduces the duration of CHECKDB against databases containing these objects.  However, the physical consistency checks of these objects is always completed.  Only when EXTENDED_LOGICAL_CHECKS option is specified will the expression evaluations be performed in addition to already present, logical checks (indexed view, XML indexes, and spatial indexes) as part of the EXTENDED_LOGICAL_CHECKS option.

 

For filtered indexes, CHECKDB has also been improved to skip records that do not qualify as being indexed by target NC index. 

This is telling me that we’ll want to have two separate CHECKDB processes, one which regularly runs CHECKDB (or CHECKTABLE) and one which occasionally runs CHECKDB with EXTENDED_LOGICAL_CHECKS.

Related Posts

Managing Central Management Server

Chrissy LeMaire shows how you can use dbatools to manage Central Management Server and registered servers: It’s a super useful feature that not all DBAs know about. Since CMS data is stored in msdb and accessible via SMO, you can access it from SQL Server Management Studio or PowerShell modules like dbatools. Central Management Server’s essential […]

Read More

Checking File Sizes In SQL Server

Andy Mallon looks back at a contribution by Junior DBA Andy, this one on checking file sizes: This is every DBA’s favorite game. Figuring out what DMV contains the data you want. It turns out there are two places that database file size info is maintained. Each database has sys.database_files which has information for that database. The […]

Read More

Categories

March 2016
MTWTFSS
« Feb Apr »
 123456
78910111213
14151617181920
21222324252627
28293031