How we dealocate the memory of a row

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How we dealocate the memory of a row

chaudharydpk0

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January 10, 2012 at 12:20 am

#391269

How we dealocate the memory of a row in a table in sql 2008 R2. please show the query if exist.

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Mike John SSCertifiable Points: 7186 More actions · Answer 1

There is not normally a need to. What exactly makes you think you should need to do this - especially fo rone row?

Normally the space will be reused a new rows are added/deleted etc. Under rare situations such as a heap table and all new data being added then huge deletes of old data you can end up with a large number of empty pages. These will be used if new rows are added or you can create a clustered index on the table to restructure it.

Mike John

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 2

Can you explain further what you want to do?

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

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

TheSQLGuru SSC Guru Points: 134017 More actions · Answer 3

chaudharydpk0 (1/10/2012)
How we dealocate the memory of a row in a table in sql 2008 R2. please show the query if exist.

You cannot do this. But like Gail I want to know WHY you THINK you want to do this. There is likely something else at play here that we could address for you.

Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service

Eric M Russell SSC Guru Points: 125519 More actions · Answer 4

chaudharydpk0 (1/10/2012)
How we dealocate the memory of a row in a table in sql 2008 R2. please show the query if exist.

OK, I'll take a stab at interpreting your request literally. When you ask how to "dealocating the memory of a row", perhaps you're asking how to deallocate memory from the buffer pool where SQL Server caches pages. SQL Server caches data at the page level, not the row level.

DBCC DROPCLEANBUFFERS

http://msdn.microsoft.com/en-us/library/ms187762.aspx

"Do not seek to follow in the footsteps of the wise. Instead, seek what they sought." - Matsuo Basho

chaudharydpk0 SSC Enthusiast Points: 148 More actions · Answer 5

Sir, actually i delete 5000 rows in my table in sql 2008 r2 but after that the table size in unchanged.

chaudharydpk0 SSC Enthusiast Points: 148 More actions · Answer 6

Sir, actually i deleted 5000 rows in my table in sql 2008 r2 but after that the table size in unchanged. I daily need to delete thousand's record in a table and in next day fill up with new data either same size or less or more size.

Suresh B. SSC-Insane Points: 22986 More actions · Answer 7

chaudharydpk0 (1/12/2012)
Sir, actually i deleted 5000 rows in my table in sql 2008 r2 but after that the table size in unchanged. I daily need to delete thousand's record in a table and in next day fill up with new data either same size or less or more size.

How did you check the table size?

Are are talking about datable files (.mdf/.ndf/.ldf) by any chance?

roasdasdb 89asdasdasd013 SSC Veteran Points: 246 More actions · Answer 8

Sounds like you are expecting the data files to automaticallly shrink, which does not happen unless explicitly set at the database level or requested on an ad-hoc bases.

Try DBCC SHRINKFILE

Use the TRUNCATEONLY option first, this should shrink the file providing the data you are deleting was more or less the last quantity of data that was inserted. Truncate will remove the free space from the end of the file and is instant, a normal shrink to a specific size will involve shuffle the data pages and this is very resource / time consuming.

For more info:

http://msdn.microsoft.com/en-us/library/ms189493.aspx

Rob

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 9

chaudharydpk0 (1/12/2012)
Sir, actually i delete 5000 rows in my table in sql 2008 r2 but after that the table size in unchanged.

Nothing unusual there. The deleted rows are scattered throughout the table. Rebuild your clustered index and the table size will drop. Avoid shrink unless you absolutely must release the space to the OS. It's better to leave free space within the database for future use. Also, unless you first rebuild the index, there will be no free pages for shrink to release as the free space will be spread throughout the table.

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

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

TheSQLGuru SSC Guru Points: 134017 More actions · Answer 10

roasdasdb 89asdasdasd013 (1/12/2012)
Sounds like you are expecting the data files to automaticallly shrink, which does not happen unless explicitly set at the database level or requested on an ad-hoc bases.
Try DBCC SHRINKFILE
Use the TRUNCATEONLY option first, this should shrink the file providing the data you are deleting was more or less the last quantity of data that was inserted. Truncate will remove the free space from the end of the file and is instant, a normal shrink to a specific size will involve shuffle the data pages and this is very resource / time consuming.
For more info:
http://msdn.microsoft.com/en-us/library/ms189493.aspx
Rob

DO NOT DO THIS.

And stop worrying about the data space for 5000 rows. You are gonna put more data into the database, and SQL Server will be able to reuse the space on those data pages.

Best,
Kevin G. Boles
SQL Server Consultant
SQL MVP 2007-2012
TheSQLGuru on googles mail service