Author Archives: Diwakar Kasibhotla

About Diwakar Kasibhotla

Oracle Database Tuning, VLDB designing, ETL/BI architect, Data Modelling, Exadata Architect.

Query Greenplum Database from Pivotal HAWQ

I was getting lot of requests on this so I decided to write a separate post. The question was how do I query a Greenplum Database (GPDB) from Pivotal HAWQ. Advertisements

Posted in Greenplum Database, MPP, Pivotal Database, Pivotal HAWQ, Web External table | Tagged , , , , | 1 Comment

Pivotal HAWQ – MPP database on HDFS

In this post I will go through the architecture of Pivotal HAWQ and how it works. I strongly suggest to go through Introduction to Massively Parallel Processing (MPP) database before reading this as you will need some concepts of MPP … Continue reading

Posted in Big Data, Hadoop, HDFS, MPP, Pivotal HAWQ, Postgress | 8 Comments

Introduction to Massively Parallel Processing (MPP)database

In Massively Parallel Processing (MPP) databases data is partitioned across multiple servers or nodes with each server/node having memory/processors to process data locally. All communication is via a network interconnect — there is no disk-level sharing or contention to be … Continue reading

Posted in Greenplum Database, MPP, Pivotal Database, Postgress | 30 Comments

Greenplum and Hadoop HDFS integration

One of the features of Greenplum 4.2 version is the use of Hadoop HDFS file system to create external tables. This is extremely useful when you want to avoid file movement from HDFS to local folder for data loading. In … Continue reading

Posted in gphdfs, Greenplum Database, Hadoop, HDFS, Postgress | 43 Comments

Installing Greenplum Database: Community Edition on a Mac OS X 10.7

Some of the key features of Greenplum Database are:     Massively Parallel Processing (MPP) Architecture for Loading and Query Processing     Polymorphic Data Storage-MultiStorage/SSD Support     Multi-level Partitioning with Dynamic Partitioning Elimination If you want to test this database on … Continue reading

Posted in Greenplum Database, Mac, MPP | Tagged , , , , , , , | 7 Comments

Parameterized views in Oracle

Last week I came across an interesting problem. Problem: I want to centralize my average assets calculation in one place and different downstream systems should be able to consume it. For example: Cognos reports should be able to use this, … Continue reading

Posted in Oracle Database, PL/SQL | Tagged , , , | Leave a comment

Exadata: 5 Adoption Roadblocks – Presentation at Oracle Openworld 2011

Here is a presentation by Robert Dawson that he did at OOW 2011. Interesting on how he correlated Exadata adoption with Grief Cycle.  These are roadblocks that nobody wants to talk about but every organization implementing Exadata will face them.

Posted in Exadata | Tagged , | 2 Comments