Netezza

Commonly used Netezza Utilities

It is very easy to perform the ETL (Extract, Transform and Load) functionalities in Netezza. Netezza supports utilities those can be used to perform the ETL/ELT operations. Below are some of commonly used Netezza utilities: Read: Commonly used Netezza Basic Commands nzload utility nzload is bulk data load utility available in Netezza. This utility supports loading data from flat file to Netezza database tables. Below is the syntax and usage: Usage: nzload -host <host> -db <database> -u <username> -pw <password> -t <target_table_name > -df /user/home/flat_file.txt by default, nzload supports '|'…

Continue ReadingCommonly used Netezza Utilities
2 Comments
September 4, 2016
Netezza

Netezza Generate Statistics: A Guide and Best Practices

Netezza uses the cost based optimizer to determine best methods determine redistribution, scan, join, join orders. The optimizer uses statistics information to determine the most efficient way to run a query. System uses the Netezza GENERATE STATISTICS command to generate information about each column proportion of the duplicate values,unique values, NULL values and the maximum and minimum values. How Statistics are collected? Netezza system collects statistics in various ways: Statistics are automatically generated for certain database operations Collect full statistics by running Netezza GENERATE STATISTICS command. This operation is required when table changes significantly, say…

Continue ReadingNetezza Generate Statistics: A Guide and Best Practices
Comments Off on Netezza Generate Statistics: A Guide and Best Practices
August 13, 2016
Netezza

Analyze and Optimize Netezza Query Performance

Analyze and Optimize Netezza Query Performance is very important part if you are performing the reporting on top of Netezza or processing large amount of data. Netezza query tuning is very important part to improve performance. Netezza uses cost based optimizer to determine the best methods for scan and join operations, orders and redistribute or broadcast operations. Netezza system may redistribute the data for some situations like joins, grouping aggregates, create tables and when loading data into Netezza tables. System will decide the redistribution based on the cost like table…

Continue ReadingAnalyze and Optimize Netezza Query Performance
Comments Off on Analyze and Optimize Netezza Query Performance
August 11, 2016
Netezza

A Guide to load data into Netezza Database

Netezza data load is transferring data into Netezza appliance. There are several ways to transfer the data into appliance. Netezza Data Load using External tables These are tables stored as flat files on the host or client systems and not in the Netezza appliance database. Create table on top of the flat file that needs to be loaded to Netezza tables, then use that external table to load target table in Netezza appliance. As a result data will be copied to the target table. Flat Files An external table allows…

Continue ReadingA Guide to load data into Netezza Database
Comments Off on A Guide to load data into Netezza Database
July 6, 2016