Category Archives: Performance Tuning for Netezza

These tips are ways to make things faster on your Netezza.

Efficient Data Upload Method Via External Table

If you ever have tried to upload data to Netezza using convention query tool methods which create individual inserts, you will know this can be EXTREMELY SLOW.  The way to upload data efficiently is to create an on-the-fly external table … Continue reading

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A Method for Handling Process Skew with Unknown Defaults

Back in the post Distributed Joins, Process Skew I mentioned a common cause of process skew were default values such as -1 for an “Unknown” customer creating skew when a redistribution happened on that customer key and there was a significant … Continue reading

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Distribution, Not Just for Joins

So I think in previous posts the need for distribution and therefore the benefit for colocation of data to handle joins has been pretty well covered.  But there are several other scenarios where data needs to be distributed to process. … Continue reading

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Distributed Joins, Process Skew

This post will build on concepts introduced in the Distributed Joins, The Basics and Distributed Joins, Modeling for Colocation posts.  I’m assuming some familiarity with table skew, where a distribution key is chosen where some key values has significantly more rows than … Continue reading

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Distributed Joins, Modeling for Colocation

This post will build on my previous post Distributed Joins, The Basics.   So we will extend the example from a customer table and an orders table, to a customer table , orders table, and order_items table.  Logically the customer skey  … Continue reading

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Distributed Joins, The Basics

This post is really about some base understanding that will be needed to understand some later performance methods.  I find to understand database performance it is helpful to understand and think how things are done at the most basic level.  … Continue reading

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Make Your Sequences 25 Times Faster

So where I work we have the need to sequence a few hundred million rows a day.  Surprisingly using a Netezza sequence object took about 2 hours on a 10200 to sequence 70 million rows.  This was acceptable for our initial … Continue reading

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