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


memory


memory

Author
Message
sandhyarao49
sandhyarao49
SSC Eights!
SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)SSC Eights! (859 reputation)

Group: General Forum Members
Points: 859 Visits: 650
I have some doubt regarding memory management.

I have sql2005 on windows server 2003 ,64-bit
suppose if have 32 gb of ram, by default how much memory it will take.

As far i concerned by default os will take 2 gb of ram and remaining will be taken by the sql server as per demand.(but i think it will take not more than 2 gb)
could any one tell me that sql serrver memory management is dynamic or not.what exactly happens

Plz give some idea regarding memory management.
Manoj-485464
Manoj-485464
Ten Centuries
Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)

Group: General Forum Members
Points: 1173 Visits: 130
SQL and os will take the Memory as they needed. If you want to strict for SQL and OS, you may need to enable the AWE on SQL server side.

Manoj

MCP, MCTS (GDBA/EDA)

Michael Earl-395764
Michael Earl-395764
One Orange Chip
One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)One Orange Chip (26K reputation)

Group: General Forum Members
Points: 26663 Visits: 23078
You are on 64 bit, so don't worry about AWE.

By default, SQL server will dynamically allocate memory. This is configurable to a window of dynamic memory (set a min and max) or you can set it to allocate a specific amount of memory.

SQL 2000 did not do an efficient job of dynamically allocating memory, but SQL 2005 does it rather well (MS made big improvements here).

Every system is different. It is best to start with dynamic memory allocation and do some performance testing to see if you need to set limits or specify memory allocation manually.
Steve Jones
Steve Jones
SSC Guru
SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)SSC Guru (276K reputation)

Group: Administrators
Points: 276811 Visits: 19896
Tend to agree with Michael. Monitor and observe the system. AWE isn't needed for 64-bit and my guess is SQL will keep building cache and run to 30GB unless you limit it.

Follow me on Twitter: @way0utwest
Forum Etiquette: How to post data/code on a forum to get the best help
My Blog: www.voiceofthedba.com
Marios Philippopoulos
Marios Philippopoulos
One Orange Chip
One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)

Group: General Forum Members
Points: 27142 Visits: 3782
To get the total current size of your buffer pool run the following:

SELECT
SUM( multi_pages_kb +
virtual_memory_committed_kb +
shared_memory_committed_kb +
awe_allocated_kb ) AS [Used by BPool, KB]
FROM
sys.dm_os_memory_clerks
WHERE
[type] = 'MEMORYCLERK_SQLBUFFERPOOL'


Taken from INSIDE MICROSOFT SQL SERVER 2005, QUERY TUNING AND OPTIMIZATION by Kalen Delaney at el., which contains a good discussion of memory issues.

Another good tool is DBCC MEMORYSTATUS. It will give you the current size of the buffer pool, plus other components, such as the procedure cache.

Here is an excerpt from the output run on my server:

Buffer Counts Buffers
------------------------------ --------------------
Committed 786432
Target 786432
Hashed 722004
Stolen Potential 127447
External Reservation 0
Min Free 128
Visible 195584
Available Paging File 401426

Procedure Cache Value
------------------------------ -----------
TotalProcs 6878
TotalPages 54239
InUsePages 105


In the above sample, the procedure cache size is 54239 pages times 8 KB/page = 434 MB (roughly)

__________________________________________________________________________________
SQL Server 2016 Columnstore Index Enhancements - System Views for Disk-Based Tables
Persisting SQL Server Index-Usage Statistics with MERGE
Turbocharge Your Database Maintenance With Service Broker: Part 2
Marios Philippopoulos
Marios Philippopoulos
One Orange Chip
One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)

Group: General Forum Members
Points: 27142 Visits: 3782
Steve Jones - Editor (5/27/2008)
Tend to agree with Michael. Monitor and observe the system. AWE isn't needed for 64-bit and my guess is SQL will keep building cache and run to 30GB unless you limit it.


It's true that because of the vast amount of virtual address space available in 64-bit, the need for AWE is greatly diminished.
However, memory allocated through AWE is locked in (will not get paged out), and that may be beneficial for app performance even in a 64-bit environment (albeit at the risk of starving other processes off of needed memory).

__________________________________________________________________________________
SQL Server 2016 Columnstore Index Enhancements - System Views for Disk-Based Tables
Persisting SQL Server Index-Usage Statistics with MERGE
Turbocharge Your Database Maintenance With Service Broker: Part 2
Wilfred van Dijk
Wilfred van Dijk
SSCarpal Tunnel
SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)

Group: General Forum Members
Points: 4344 Visits: 1363
You need AWE to prevent memory stealing by the OS.
Also make sure you have a minimum and maximum size. Don't set the maximum size to unlimited, or SQL will compete with your OS for the last MBs.
We have the same configuration and our max memorysize is 28GB (min size is 16GB)

Also, be aware of memory trashing if you do a large OS filecopy on that server.
You also get memory messages in your logfile when adding/deleting databases/snapshots, but these are ok.

Wilfred
The best things in life are the simple things
Manoj-485464
Manoj-485464
Ten Centuries
Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)Ten Centuries (1.2K reputation)

Group: General Forum Members
Points: 1173 Visits: 130
I agree with Wilfred van Dijk. Wilfred van Dijk has explined very clearly.

Manoj

MCP, MCTS (GDBA/EDA)

Marios Philippopoulos
Marios Philippopoulos
One Orange Chip
One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)One Orange Chip (27K reputation)

Group: General Forum Members
Points: 27142 Visits: 3782
Wilfred van Dijk (5/27/2008)
You need AWE to prevent memory stealing by the OS.
Also make sure you have a minimum and maximum size. Don't set the maximum size to unlimited, or SQL will compete with your OS for the last MBs.
We have the same configuration and our max memorysize is 28GB (min size is 16GB)

Also, be aware of memory trashing if you do a large OS filecopy on that server.
You also get memory messages in your logfile when adding/deleting databases/snapshots, but these are ok.


Memory stealing is not a concern, unless there are other non-OS essential apps running on the server, correct? (I'm thinking Exchange for example).

Are there other occasions where mem stealing would be an issue?

__________________________________________________________________________________
SQL Server 2016 Columnstore Index Enhancements - System Views for Disk-Based Tables
Persisting SQL Server Index-Usage Statistics with MERGE
Turbocharge Your Database Maintenance With Service Broker: Part 2
Wilfred van Dijk
Wilfred van Dijk
SSCarpal Tunnel
SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)SSCarpal Tunnel (4.3K reputation)

Group: General Forum Members
Points: 4344 Visits: 1363
If you don't enable AWE on a 64bit server you can get errors like "A significant part of sql server process memory has been paged out. This may result in performance degradation". for example, this can happen if you copy a lage filebackup to another server.
As a result, al your SQL processes are suspending, but I would say dying (I've had that experience) Blush

Read the following articles:

http://blogs.msdn.com/psssql/archive/2007/05/31/the-sql-server-working-set-message.aspx
http://support.microsoft.com/kb/918483
http://msmvps.com/blogs/omar/archive/2007/09/19/a-significant-part-of-sql-server-process-memory-has-been-paged-out-this-may-result-in-performance-degradation.aspx
http://www.mcse.ms/message2444910.html
http://blogs.msdn.com/slavao/archive/2005/04/29/413425.aspx

Wilfred
The best things in life are the simple things
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