In over six years of doing data warehouse POCs and benchmarks for clients there is one area that I frequently see as problematic: “batch jobs”. Most of the time these “batch jobs” take the form of some PL/SQL procedures and packages that generally perform some data load, transformation, processing or something...
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Tags: Exadata, Oracle Exadata, row processing, set processing
Posted in Data Warehousing, Exadata, Oracle, Performance, SQL Tuning, VLDB | 21 Comments »
Getting flat file data into your Oracle data warehouse is likely a daily (or more possibly frequent) task, but it certainly does not have to be a difficult one. Bulk loading data rates are governed by the following operations and hardware resources: How fast can the data be read How fast can data be...
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Tags: data loading, external tables, sql*loader, sqlldr
Posted in Data Warehousing, Oracle, VLDB | 13 Comments »

Leveraging Oracle’s Parallel Execution (PX) in your Oracle data warehouse is probably the most important feature/technology one can use to speed up operations on large data sets. PX is not, however, “go fast” magic pixi dust for any old operation (if thats what you think, you probably don’t understand the parallel...
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Tags: Data Warehousing, Oracle, Parallel Execution, parallel query, scalability
Posted in Data Warehousing, Oracle, Parallel Execution, Performance, VLDB | 8 Comments »
Partitioning is an essential performance feature for an Oracle data warehouse because partition elimination (or partition pruning) generally results in the elimination of a significant amount of table data to be scanned. This results in a need for less system resources and improved query performance. Someone once told me “the fastest...
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Tags: Data Warehousing, managability, Oracle, partitioning, Performance
Posted in Data Warehousing, Oracle, Performance, VLDB | 10 Comments »
Editor’s note: This blog post does not cover Exadata Hybrid Columnar Compression. The first thing that comes to most people’s mind when database table compression is mentioned is the savings it yields in terms of disk space. While reducing the footprint of data on disk is relevant, I would argue it...
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Tags: compression, data warehouse, Oracle
Posted in Data Warehousing, Oracle, Performance, VLDB | 8 Comments »

If you want to build a house that will stand the test of time, you need to build on a solid foundation. The same goes for architecting computer systems that run databases. If the underlying hardware is not sized appropriately it will likely lead to people blaming software. All too often...
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Tags: capacity planing, data warehouse, Data Warehousing, io bandwidth, Oracle, Performance, scan rate
Posted in Data Warehousing, Oracle, Performance, VLDB | 16 Comments »
At the 2009 Oracle OpenWorld Unconference back in October I lead a chalk and talk session entitled The Core Performance Fundamentals Of Oracle Data Warehousing. Since this was a chalk and talk I spared the audience any powerpoint slides but I had several people request that make it into a presentation so they could...
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Tags: data warehouse, Data Warehousing, Oracle, Performance
Posted in Data Warehousing, Exadata, Oracle, Performance, VLDB | 16 Comments »
Even though Oracle OpenWorld 2009 is a few months away, I thought I would take a moment to mention that the Oracle Real-World Performance Group will again be hosting three sessions. Hopefully you are no stranger to our Oracle database performance sessions and this year we have what I think will be a very...
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Tags: Exadata, openworld 2009, oracle database machine, Real-World Performance Group
Posted in Exadata, Oracle, Performance, VLDB | 6 Comments »

A number of weeks back I had come across a paper/presentation by Riyaj Shamsudeen entitled Battle of the Nodes: RAC Performance Myths (avaiable here). As I was looking through it I saw one example that struck me as very odd (Myth #3 – Interconnect Performance) and I contacted him about it. After further review...
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Tags: interconnect traffic, Parallel Execution, parallel query
Posted in Data Warehousing, Oracle, Parallel Execution, Performance, VLDB | 15 Comments »
Today, June 10th, marks the Yahoo! Hadoop Summit ’09 and the crew at Facebook have a writeup on the Facebook Engineering page entitled: Hive – A Petabyte Scale Data Warehouse Using Hadoop. I found this an very interesting read given some of the Hadoop/MapReduce comments from David J. DeWitt and Michael Stonebraker as well...
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Tags: data warehouse, facebook, hadoop, hive, MapReduce, petabyte scale
Posted in Data Warehousing, VLDB | 4 Comments »
There are many ways to design tables/schemas and many ways to write SQL queries that execute against those tables/schemas. Some designs are better than others for various reasons, however, I think that frequently people underestimate the power of SQL (for both “good” and “evil”). All too often in data warehouses, I see tables designed...
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Tags: pivot, pivot table, star schema, table design, unpivot
Posted in 11gR1, Data Warehousing, Execution Plans, Oracle, SQL Tuning, VLDB | 7 Comments »
Chuck Hollis, VP and Global Marketing CTO at EMC has written a couple blog posts offering his thoughts on Oracle Exadata. The first was “Oracle Does Hardware” which he wrote the day after the product launch. The second, unimpressively titled “I Annoy Kevin Closson at Oracle” was on Monday October 20th which was in...
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Tags: data bandwidth, Exedata, fibre channel storatge, Oracle, SAN Storage, scan rate
Posted in Exadata, Oracle, Performance, VLDB | 15 Comments »