FIX: Joins with a UNION ALL View May Take a Long Time to Compile and May Use Large Amounts of Memory (327562)
The information in this article applies to:
- Microsoft SQL Server 2000 (all editions)
This article was previously published under Q327562 BUG #: 361283 (SHILOH_BUGS) SYMPTOMS Queries that join several tables and a view that contains a
UNION ALL statement may take a long time to optimize and may cause the
optimizer to use a lot of memory. Under certain conditions, the query might use
as much as 80 percent of the memory allocated by SQL Server. If that is the
case, the query, or other queries, might fail and you receive the following
error message: Msg 701, Level 17, State 99, Line 1
There is insufficient system memory to run this query. During the
compilation of the query (even after the 701 error occurs), other user
connections might experience slow performance and it may appear that SQL Server
has stopped responding. RESOLUTION To resolve this problem, obtain the latest
service pack for Microsoft SQL Server 2000. For additional information, click
the following article number to view the article in the Microsoft Knowledge
Base: 290211 INF: How To Obtain the Latest SQL Server 2000 Service Pack NOTE: The following hotfix was created before the release of Microsoft
SQL Server 2000 Service Pack 3. 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
------------------------------------------------------
8/6/2002 13:09 8.00.0674 7293 KB Sqlservr.exe
NOTE: Because of file dependencies, the most recent hotfix or feature
that contains the files may also contain additional
files. STATUSMicrosoft
has confirmed that this is a problem in the Microsoft products that are listed
at the beginning of this article.
This problem was first corrected in Microsoft SQL Server
2000 Service Pack 3.MORE INFORMATION The fix compares union-all operators based on a set of
columns. The exploration phase ends as soon as SQL Server recognizes that the
set of columns are logically the same (only their order is
different).
You can characterize the memory usage behavior by using
Performance Monitor. Note that the object: [Memory Manager -> Optimizer Memory] exhibits continuous growth while the query is being run.
Modification Type: | Minor | Last Reviewed: | 9/27/2005 |
---|
Keywords: | kbHotfixServer kbQFE kbbug kbfix kbSQLServ2000preSP3fix kbSQLServ2000sp3fix KB327562 |
---|
|