Link to home
Start Free TrialLog in
Avatar of deepakee
deepakee

asked on

negative value when I run sp_spaceused


I’ve run sp_spaceused against a table and I got as unused space the value of – (minus) 8KB, which is the size of a data page.

I’ve checked the filegroup that this table belongs to and there is free space for that filegroup.

How come this negative value?

Do I have to do something?

Thank you,
Deepak
ASKER CERTIFIED SOLUTION
Avatar of Aneesh
Aneesh
Flag of Canada image

Link to home
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
Start Free Trial
Avatar of deepakee
deepakee

ASKER

From BOL regarding running updateusage:

"Use it only when you suspect incorrect values are being returned and when the process will not have an adverse effect on other users or processes in the database. If preferred, DBCC UPDATEUSAGE can be run separately."

1) What are the " adverse effect on other users or processes in the database" when running DBCC UPDATEUSAGE?

2) Is it only a performance issue?

2) Any issue with the actual data?

The -ve value returned by sp_SpaceUsed may be, because of the operations such asl arge delete/update on the tables or dropping of indexes. In such a situations information in the sysindexes tables may not be updated. .

>1) What are the " adverse effect on other users or processes in the database" when running DBCC UPDATEUSAGE?
DBCC Commands take lot of IO and CPU Resources, So Make sure that the CPU is not busy, and you have enough space left in tempDB