INF: Distributed Queries are not Run as Parallel Query Steps (271669)


The information in this article applies to:

  • Microsoft SQL Server 7.0
  • Microsoft SQL Server 2000 (all editions)
This article was previously published under Q271669

SUMMARY

Starting with SQL Server 7.0, the SQL Server engine introduces the ability to run a given query with multiple threads. This is often termed as running a command in parallel or "across two or more CPUs."

Starting with SQL Server 7.0 the SQL Server engine also introduces the ability to query remote data sources by using the OLE-DB interface.

For additional information, refer to the "Linked Servers" topic in SQL Server Books Online.

Due to limitations in certain OLE-DB providers the Linked Query steps are serialized.

MORE INFORMATION

There are operators, such as unions, that may lend themselves to parallel execution. Limitations of certain OLE-DB providers, collation sequences, the ability to gather detailed statistical information and other factors currently limit SQL Server to serialized operations.

Future versions of SQL Server may extend the capabilities where appropriate.
Modification Type:MajorLast Reviewed:10/16/2003
Keywords:kbinfo KB271669
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