|
|
|
SSC-Enthusiastic
      
Group: General Forum Members
Last Login: Yesterday @ 1:51 AM
Points: 183,
Visits: 947
|
|
I am defragmenting the database as a maintenance work. But i found that some of the databases avg_fragmentation_in_percent does not reduce.But in some article i have seen that fragmentation on small indexes is often not controllable and The pages of small indexes are stored on mixed extents. So what is the limit for page count for which i can neglect the value of avg_fragmentation_in_percent?
In some databases having page count 100 has shown reduce in fragmentation but some db having page count 68 does not reduce fragmentation. So how can i decide for which condition i should consider checking fragmentation?
|
|
|
|
|
SSC-Dedicated
           
Group: General Forum Members
Last Login: Today @ 12:38 AM
Points: 37,725,
Visits: 29,981
|
|
68 pages is too small to worry about. The usual threshold that's mentioned is 1000 pages. Not a hard and fast number, just a guide
Gail Shaw Microsoft Certified Master: SQL Server 2008, MVP SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
We walk in the dark places no others will enter We stand on the bridge and no one may pass
|
|
|
|
|
SSCertifiable
       
Group: General Forum Members
Last Login: Yesterday @ 11:46 PM
Points: 5,202,
Visits: 11,156
|
|
Aside what Gail has said check the index id for the object. If its a heap then it will naturally contain some fragmentation.
The page allocation marker is 8 pages, any allocations over that will use uniform extents. This is detailed on msdn, sorry but I don't have link at present.
-----------------------------------------------------------------------------------------------------------
"Ya can't make an omelette without breaking just a few eggs"
|
|
|
|