SQL Clone
SQLServerCentral is supported by Redgate
 
Log in  ::  Register  ::  Not logged in
 
 
 


Page Splits And Fill Factor


Page Splits And Fill Factor

Author
Message
pradeep_pvn
pradeep_pvn
Valued Member
Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)

Group: General Forum Members
Points: 50 Visits: 38
Page Splits
-------------
When page split happens - which part of the row is moved? Is the whole row copied to a new location [or] that part of the row which cannot be accommodated is copied over?.

Fill Factor
-----------

"Page spilts will be reduced by specifying fill factor"

This is something I read and got confused thinking about the inserts and updates. There is a certain % of space that will be reserved on setting the fill factor (Okay accepted !!). But, Is the space reservation applied only when entering the data for the first time in the page?

Will the reservation space be consumed while updating and inserting new records? Is this how fill factor help in update and insert.
bitbucket-25253
bitbucket-25253
SSCoach
SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)SSCoach (15K reputation)

Group: General Forum Members
Points: 15699 Visits: 25280
For a good discussion of why page splits occur and what happens, read the following (It contains sample code and results to make understanding much easier)

http://sqlblogcasts.com/blogs/tonyrogerson/archive/2007/06/28/what-is-a-page-split-what-happens-why-does-it-happen-why-worry.aspx

The above blog also contains this link, (to a Paul Randal blog post) which further explains (with sample code) what occurs / causes page splits.
http://blogs.msdn.com/b/sqlserverstorageengine/archive/2006/12/13/more-undocumented-fun_3a00_-dbcc-ind_2c00_-dbcc-page_2c00_-and-off_2d00_row-columns.aspx

Corrected spelling of Paul Randal's name

If everything seems to be going well, you have obviously overlooked something.

Ron

Please help us, help you -before posting a question please read

Before posting a performance problem please read
pradeep_pvn
pradeep_pvn
Valued Member
Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)

Group: General Forum Members
Points: 50 Visits: 38
Thank you

According to the blog .. The complete row is transferred to the new page. But it still does not answer my question about the Fill Factor. May be I need to do more study on this topic.

Anyways, Thanks again for the reply.
Stefan_G
Stefan_G
Ten Centuries
Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)Ten Centuries (1.3K reputation)

Group: General Forum Members
Points: 1305 Visits: 961
The fill factor only applies when an index is created or rebuilt.

SQL server does not try to maintain the fill factor when updating or inserting values.

Quote from BOL:

The fill factor setting applies only when the index is created, or rebuilt. The SQL Server Database Engine does not dynamically keep the specified percentage of empty space in the pages. Trying to maintain the extra space on the data pages would defeat the purpose of fill factor because the Database Engine would have to perform page splits to maintain the percentage of free space specified by the fill factor on each page as data is entered.

pradeep_pvn
pradeep_pvn
Valued Member
Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)Valued Member (50 reputation)

Group: General Forum Members
Points: 50 Visits: 38
Excellent ! Just the answer I was looking for. Thank you steven.

Here is an extract from microsoft url about the fill factor.
http://msdn.microsoft.com/en-us/library/aa196711(SQL.80).aspx
Go


Permissions

You can't post new topics.
You can't post topic replies.
You can't post new polls.
You can't post replies to polls.
You can't edit your own topics.
You can't delete your own topics.
You can't edit other topics.
You can't delete other topics.
You can't edit your own posts.
You can't edit other posts.
You can't delete your own posts.
You can't delete other posts.
You can't post events.
You can't edit your own events.
You can't edit other events.
You can't delete your own events.
You can't delete other events.
You can't send private messages.
You can't send emails.
You can read topics.
You can't vote in polls.
You can't upload attachments.
You can download attachments.
You can't post HTML code.
You can't edit HTML code.
You can't post IFCode.
You can't post JavaScript.
You can post emoticons.
You can't post or upload images.

Select a forum

































































































































































SQLServerCentral


Search