Netezza

Netezza Implicit Skew with an Example

Netezza Implicit Skew is the Netezza skew that occurs within the database when processing large data sets. The implicit Netezza skew are very difficult to identify. You can read more on Netezza Skew and How to avoid it. Netezza Implicit Skew Netezza implicit skew is occurs when data get redistributed or broadcasted on some other column to perform join operations. Data will be redistributed or broadcasted to perform co-located joins. The column on which data get redistributed or joined could be skewed that is, most of the redistributed data get inserted to…

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May 5, 2017
BigData

Different Hive Join Types and Examples

Join is a clause that is used for combining specific fields from two or more tables based on the common columns. The joins in the hive are similar to the SQL joins. Joins are used to combine rows from multiple tables. In this article, we will learn about different Hive join types with examples. Read: Hadoop Hive Bucket Concept and Bucketing Examples Hive Create Table Command and Examples Hive Create View Syntax and Examples Below are the tables that we will be using to demonstrate different Join types in Hive:…

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May 4, 2017
Data Warehouse

Data Warehouse Three-tier Architecture in Details

Usually, data warehouse adapts the three-tier architecture. In this article, we will discuss on the data warehouse three-tier architecture. You can read about read about two-tier architecture in my other post 'Data Warehouse Two-tier architecture in details' Data Warehouse Three-tier Architecture Following are the three-tiers of data warehouse architecture: Bottom Tier The bottom tier of the architecture is the data warehouse database server. It is usually the relational database (RDBMS) system. Data from operational databases and external sources are extracted using application program interfaces and ETL/ELT utilities. You generally use…

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May 4, 2017
BigData

Commonly used Hadoop Hive Commands and Examples

If you are already familiar with the SQL then Hive command syntax are easy to understand. In this article, we will discuss on the commonly used Hadoop Hive commands. Read: Cloudera Impala Generate Sequence Numbers without UDF Netezza ROWNUM Pseudo Column Alternative Run Impala SQL Script File Passing argument and Working Example  An Introduction to Hadoop Cloudera Impala Architecture Commonly used Hadoop Hive commands Below are the most commonly used Hadoop Hive commands: Hive Create Database A database is a collection of namespace in Hive. Below is the syntax to…

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May 3, 2017
Data Warehouse

Data Warehouse Physical Data Model

The Data warehouse physical data model describes how the model will be built in the database. A physical database model shows all table structures, including column name, column data type, column constraints, primary key, foreign key, and relationships between tables. Read: Data Warehouse Project Life Cycle and Design Star Schema model in Data Warehouse Snowflake Schem Model in Data Warehouse Step by Step Guide to Dimensional Data Modeling Slowly Changing Dimensions (SCD) in Data Warehouse Rapidly Changing Dimension in Data Warehouse Features of Data Warehouse Physical Data Model Following are…

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April 23, 2017
Data Warehouse

Data Warehouse Logical Data Model

A Data warehouse logical data model describes model in more detail compared to the Data Warehouse conceptual data model. A data warehouse logical data model describes the data in as much detail as possible, this model does not describe how the model is implemented. Read: Star Schema model in Data Warehouse Snowflake Schem Model in Data Warehouse Step by Step Guide to Dimensional Data Modeling Slowly Changing Dimensions (SCD) in Data Warehouse Rapidly Changing Dimension in Data Warehouse Data Warehouse Three-tier Architecture in Details Features of Data Warehouse Logical Data…

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April 23, 2017
Data Warehouse

Data Warehouse Conceptual Data Model

A Data warehouse conceptual data model is nothing but a highest-level relationships between the different entities (in other word different table) in the data model. Read: Star Schema model in Data Warehouse Snowflake Schem Model in Data Warehouse Step by Step Guide to Dimensional Data Modeling Slowly Changing Dimensions (SCD) in Data Warehouse Rapidly Changing Dimension in Data Warehouse Data Warehouse Three-tier Architecture in Details Features of Data Warehouse Conceptual Data Model Following are the features of conceptual data model: This is initial or high level relation between different entities…

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April 23, 2017
Netezza

Netezza Count Records from all Tables in Database and Example

Let us assume you are migration data from one Netezza server to other or new higher version Netezza server. Once the migration is completed, you have to perform some mandatory checks such as availability of objects, compare count of all table between two servers. In this article, we will discuss on Netezza Count Records from all Tables in Database and some Example. Check: IBM Netezza Count All Database Objects – System Table Query Netezza Pivot  Rows to Column with Example IBM Netezza Split Delimited Fields into Table Records and Examples…

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April 22, 2017
Netezza

Netezza nzload merge Operations

You can insert new records and update existing by using nzload command itself. In this article, we will discuss about the new feature introduced in nzload. Netezza version 7.2.x supports the Netezza nzload merge operations. Netezza nzload merge operations The Netezza nzload command now supports merge operations to enable this new feature you must use three new options in nzload: -merge option—Specifies whether to merge the contents of the data file into the target table by inserting rows, updating rows, or both INSERT - Inserts new rows into the table. UPDATE…

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April 14, 2017
Netezza

Netezza nzload Control file and Syntax with an Examples

Like any other database such as Oracle, Netezza also allows you to load data using control files. In this article, we will discuss about the Netezza nzload control files and its syntax with examples. Using a nzload control file, you can define load operations in a text file instead of having to specify options on the command line. You can specify the information such as data file name, log file details etc in control file. You can also use control files to run multiple concurrent table loads, with different options…

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April 14, 2017