Introduction; Tpc Benchmark D (Tpc-D); Dss Vs. Oltp; Oracle Overview - Compaq 112726-001 - ProLiant - 6500 White Paper

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Introduction

The purpose of this document is to share the knowledge acquired by Compaq Systems Engineers in the
area of configuration and performance tuning of Decision Support Systems using the Oracle8 Database
and Microsoft Windows NT on Compaq servers. The system tested by Compaq represents a single query
stream TPC Benchmark D (TPC-D) on the Compaq ProLiant family of Servers. General information and
query data for the TPC-D benchmark are included in this paper. It is our desire to deliver the best
technical information possible on a specific topic in a timely manner and in a highly useable format. Any
comments, suggestions and feedback are always appreciated.

TPC Benchmark D (TPC-D)

The TPC Benchmark D is a decision support benchmark, which consists of business oriented ad-hoc
queries and concurrent updates. The benchmark illustrates decision support systems that examine large
volumes of data; execute queries with a high degree of complexity; and gives answers to critical business
questions. The TPC-D benchmark evaluates performance of various decision support systems by the
execution of sets of seventeen queries against a standard database. Appendix A of this document contains
the schema of the TPC-D database, appendix B contains descriptions of each of the seventeen queries, and
appendix C contains the SQL code for each of the seventeen queries used in the TPC-D benchmark
examples. A full description of the TPC-D specification is available from the Transaction Processing
Performance Council (Phone: 408-295-8894, Web site: www.tpc.org/dspec.html).

DSS vs. OLTP

Decision Support Systems (DSS) is a term used to describe the capability of a system to support the
formulation of business decisions through complex queries against a database. It can also specifically refer
to a database which is intended for this purpose, as opposed to one which primarily supports on-line
transaction processing (OLTP) operations. Decision Support is different from OLTP. OLTP applications
are update-intensive and generally consist of shorter transactions that access a small portion of a database,
often through a primary key or index. Decision support applications typically consist of long and often
complex read-only queries that access large portions of the database. Decision support databases are
updated relatively infrequently, either by periodic batch runs, or by background "trickle" update streams.
The database need not contain real-time or up-to-the-minute information, as decision support applications
tend to process large amounts of data which usually would not be affected significantly by individual
transactions.

Oracle Overview

The information in this document contains information related to Oracle8 Server version 8.0.4 for
Windows NT version 4.0 or later. Because there is information available concerning generic tuning of
Oracle8 Server, this document focuses on specific tuning suggestions for DSS on Compaq servers and
Windows NT. A section on general Oracle8 architecture is included as a part of the Oracle Overview.
Tuning sections follow the Oracle Overview. Wherever possible, this White Paper references other useful
tuning documentation.

Architecture

Oracle8 Server for Windows NT is a 32-bit Windows NT application. Oracle8 Server is
implemented on Windows NT as a single process, multi-threaded architecture. Each Oracle8
Server instance consists of a single process with multiple threads. The number of threads
associated with the Oracle8 Server process varies depending upon options selected (background
threads) and user connections (shadow threads). Note that Compaq disk subsystems provide
asynchronous I/O, therefore no DBWR and LGWR I/O slave threads are required. The
maximum number of shadow threads, and thus the maximum number of user connections, is
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DSS Sizing and Tuning of Oracle8 for Windows NT on Compaq Servers
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