Microsoft KB Archive/831999

= FIX: An AWE system uses more memory for sorting or for hashing than a non-AWE system in SQL Server 2000 =

Article ID: 831999

Article Last Modified on 11/2/2007

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APPLIES TO


 * Microsoft SQL Server 2000 Developer Edition
 * Microsoft SQL Server 2000 Standard Edition
 * Microsoft SQL Server 2000 Enterprise Edition
 * Microsoft SQL Server 2000 Personal Edition
 * Microsoft SQL Server 2000 Enterprise Edition
 * Microsoft SQL Server 2000 Workgroup Edition
 * Microsoft SQL Server 2000 Developer Edition
 * Microsoft SQL Server 2000 Enterprise Edition 64-bit

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Bug #: 469995 (Shiloh_bugs)



SYMPTOMS
The memory that SQL Server uses during sorting and hashing operations is allocated from the buffer pool as a stolen buffer. Stolen buffers must always remain in the virtual address space. They cannot be unmapped to a Microsoft Windows 2000 Address Windowing Extensions (AWE) location. SQL Server uses a throttle to limit how much memory can be used for sorting and for hashing. SQL Server limits the memory for these reasons:


 * So that the whole buffer pool will not be consumed by stolen buffers.
 * So that the buffer pool can continue to serve as a data cache.

On systems with AWE enabled, the computation of how much memory can be used as workspace memory for sorting and for hashing is sometimes higher than it is on a non-AWE system. Because stolen buffers must always remain in the address space, the additional AWE memory should be irrelevant to this computation. The fix that is discussed in this article corrects the problem so that the computation of the workspace available for sorting and for hashing is consistent across both configurations.

Because of the miscalculation, sort and hash operations may try to use more memory from the buffer pool than can remain mapped. As a result, a BPool::Map error that is similar to the following is written to the SQL Server error log followed by the output of the DBCC MEMORYSTATUS command:

2003-06-23 04:17:14.86 spid153 BPool::Map: no remappable address found.

2003-06-23 04:17:15.04 spid92 Buffer Distribution: Stolen=133972 Free=10785 Procedures=17346 Inram=0 Dirty=155429 Kept=0 I/O=2, Latched=988, Other=513478

2003-06-23 04:17:15.06 spid92 Buffer Counts: Commited=832000 Target=832000 Hashed=669897 InternalReservation=1514 ExternalReservation=4255 Min Free=1024

2003-06-23 04:17:15.06 spid92 Procedure Cache: TotalProcs=8505 TotalPages=17346 InUsePages=6439

2003-06-23 04:17:15.06 spid92 Dynamic Memory Manager: Stolen=25253 OS Reserved=1776 OS Committed=1735 OS In Use=1644 Query Plan=17383 Optimizer=0 General=7999 Utilities=243 Connection=907

2003-06-23 04:17:15.06 spid92 Global Memory Objects: Resource=3259 Locks=102 SQLCache=773 Replication=2 LockBytes=2 ServerGlobal=3528 Xact=110

2003-06-23 04:17:15.06 spid92 Query Memory Manager: Grants=6 Waiting=0 Maximum=140712 Available=10409

In the output that is shown earlier, you can see that SQL Server will allow multiple queries that are requesting a total of 140712 buffers to run concurrently. In the earlier example, there are six queries that are executing with sorts or with hashes. These six queries have been granted the use of 130303 buffers (140712 - 10409 = 130303).



Service pack information
To resolve this problem, obtain the latest service pack for Microsoft SQL Server 2000. For more information, click the following article number to view the article in the Microsoft Knowledge Base:

290211 How to obtain the latest SQL Server 2000 service pack

Hotfix information
The English version of this fix has the file attributes (or later) that are listed in the following table. The dates and times for these files are listed in coordinated universal time (UTC). When you view the file information, it is converted to local time. To find the difference between UTC and local time, use the Time Zone tab in the Date and Time tool in Control Panel.   Date         Time   Version            Size    File name --  31-May-2003  18:45  2000.80.818.0      78,400  Console.exe 28-Oct-2003 04:21  2000.80.873.0     315,968  Custtask.dll 02-Oct-2003 20:59  2000.80.867.0      33,340  Dbmslpcn.dll 25-Apr-2003 02:12                    786,432  Distmdl.ldf 25-Apr-2003 02:12                  2,359,296  Distmdl.mdf 30-Jan-2003 01:55                        180  Drop_repl_hotfix.sql 12-Sep-2003 03:26  2000.80.859.0   1,905,216  Dtspkg.dll 26-Aug-2003 20:16  2000.80.854.0     528,960  Dtspump.dll 23-Jun-2003 22:40  2000.80.837.0   1,557,052  Dtsui.dll 23-Jun-2003 22:40  2000.80.837.0     639,552  Dtswiz.dll 24-Apr-2003 02:51                    747,927  Instdist.sql 03-May-2003 01:56                      1,581  Inst_repl_hotfix.sql 08-Feb-2003 06:40  2000.80.765.0      90,692  Msgprox.dll 01-Apr-2003 02:07                      1,873  Odsole.sql 05-Apr-2003 01:46  2000.80.800.0      62,024  Odsole70.dll 07-May-2003 20:41  2000.80.819.0      25,144  Opends60.dll 02-Apr-2003 21:48  2000.80.796.0      57,904  Osql.exe 02-Apr-2003 23:15  2000.80.797.0     279,104  Pfutil80.dll 04-Aug-2003 18:17                    550,780  Procsyst.sql 12-Sep-2003 00:37                     12,305  Qfe469315.sql 22-May-2003 22:57                     19,195  Qfe469571.sql 06-Sep-2003 01:36                  1,090,932  Replmerg.sql 06-Sep-2003 07:18  2000.80.858.0     221,768  Replprov.dll 06-Sep-2003 07:18  2000.80.858.0     307,784  Replrec.dll 06-Sep-2003 00:00                  1,087,150  Replsys.sql 13-Aug-2003 16:28                    986,603  Repltran.sql 22-Oct-2003 00:08  2000.80.871.0      57,916  Semnt.dll 29-Jul-2003 20:13  2000.80.819.0     492,096  Semobj.dll 31-May-2003 18:27  2000.80.818.0     172,032  Semobj.rll 05-Aug-2003 21:06                    127,884  Sp3_serv_uni.sql 01-Jun-2003 01:01  2000.80.818.0   4,215,360  Sqldmo.dll 07-Apr-2003 17:44                     25,172  Sqldumper.exe 19-Mar-2003 18:20  2000.80.789.0      28,672  Sqlevn70.rll 27-Sep-2003 04:42  2000.80.865.0     180,792  Sqlmap70.dll 03-Sep-2003 02:56  2000.80.857.0     188,992  Sqlmmc.dll 02-Sep-2003 23:03  2000.80.857.0     479,232  Sqlmmc.rll 22-Oct-2003 00:08  2000.80.871.0     401,984  Sqlqry.dll 08-Feb-2003 06:40  2000.80.765.0      57,920  Sqlrepss.dll 05-Nov-2003 20:52  2000.80.876.0   7,606,353  Sqlservr.exe 25-Jul-2003 21:44  2000.80.845.0     590,396  Sqlsort.dll 08-Feb-2003 06:40  2000.80.765.0      45,644  Sqlvdi.dll 02-Oct-2003 20:59  2000.80.867.0      33,340  Ssmslpcn.dll 01-Jun-2003 01:01  2000.80.818.0      82,492  Ssnetlib.dll 01-Jun-2003 01:01  2000.80.818.0      25,148  Ssnmpn70.dll 28-Oct-2003 04:21  2000.80.873.0     123,456  Stardds.dll 01-Jun-2003 01:01  2000.80.818.0     158,240  Svrnetcn.dll 31-May-2003 18:59  2000.80.818.0      76,416  Svrnetcn.exe 30-Apr-2003 23:52  2000.80.816.0      45,132  Ums.dll 02-Jul-2003 00:19  2000.80.834.0      98,816  Xpweb70.dll Note Because of file dependencies, the most recent hotfix or feature that contains these files may also contain additional files.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the &quot;Applies to&quot; section.

This problem was first corrected in Microsoft SQL Server 2000 Service Pack 4.



MORE INFORMATION
If the BPool::Map error occurs while a DBCC DBREINDEX statement or a CREATE INDEX statement is running, see the following article in the Microsoft Knowledge Base:

838459 FIX: You may receive a BPool::Map warning when you create or rebuild indexes by using the awe enabled configuration option

Microsoft Knowledge Base article 838459 discusses a fix that may be more likely to explain the true cause of the error.

