November 24, 2013 at 2:53 am
i have a quick question about internal fragmentation
the book explanation is that DML statement cause internal fragmentation, i can understand how UPDATE and DELETE leads to fragmentation but i don't understand how INSERT does
can anyone please explain this to me
November 24, 2013 at 6:06 am
Depends what the book means by 'internal fragmentation'. It's a poorly defined term that has been used for different things by different people.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
November 24, 2013 at 6:33 am
the fragmentation that is caused by pages not being filled
November 24, 2013 at 12:05 pm
Better term for that is 'low page density'.
Inserts and updates can cause page splits, which results in pages half full. Deletes can leave empty gaps on pages where the row used to be.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
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