The IBM Netezza system has four user priority levels for session query and execution. Other two more priorities are for system resources. In this article, we will check on how to change Netezza user query priority with syntax and examples. Netezza Priority Levels Below table describe the Netezza user priority levels: Name Description Critical Highest priority user High Priority user job. The high priority jobs takes precedence’s over normal jobs Normal Default priority level for all jobs Low Lowest priority user jobs Change Priority of Jobs in a Session You…

Optimizing the Netezza table is very important aspect to speed up your data loading and unloading process. In this article, we will check out some tricks to optimize Netezza table structure to improve performance. There are no specific set of rules to optimize Netezza table structure. But here I have listed some of methods that I use while designing table for better performance. Read: Change Netezza User Query Priority – Syntax and Examples Netezza Create Table and Syntax Optimize Netezza Table Structure Typically, when you create the aggregate table or…

Netezza uses a cost-based optimizer to determine the best method for scan and join operations, join order, and data movement between SPUs, that is, redistribute or broadcast operations. You can use the Netezza EXPLAIN command to display the actual execution plan that Netezza generates and uses while executing any query in the system. Netezza Optimizer Netezza uses the cost based optimizer to determine the best methods for the query to be executed in the Netezza system. Optimizer uses the statistics to determine the optimal and best execution plan for Netezza…

Netezza data warehouse appliance does soft delete until the groom process is performed. Netezza logically deletes the rows by flagging deletexid. The data will be there in the system and you can recover the same whenever you accidentally delete the rows from the table. In this article, We will check how to perform Netezza recover deleted rows. Netezza Recover Deleted Rows Every table has the system columns such as createxid, deletexid and rowid. You can check the column by querying these columns from the table. Whenever you delete the record…

The Netezza rollup functionality gives aggregation results at multiple grouping levels in a single result set. In this article, we will check Netezza rollup group aggregates using grouping sets. Netezza Rollup Group Aggregates using Grouping sets You may want to aggregate the records in the tables for each records partition in the group. For examples, consider you want to find out sum of salary of the all employees in the department as a different rows in the query result (row with NULL employee name as highlighted in the image). To…

When you create a table in IBM Netezza, the table usually does not take any space on the data slices. Once you insert the rows then only system allocates the space to the rows. In this article, we will see the Netezza table row size details and what are the system columns and their size when you insert rows into the created table. Netezza Table Row Size Details When you insert new row to the created table, IBM Netezza system allocates at least one extent of size 3 MB of…

Life is much easier if you use any query tools to access Netezza nzsql queries. Some people do not like to use specific tool, instead they use Netezza command line. In this article, we will check on Netezza nzsql Query Buffer to edit command line Queries. Netezza nzsql Query Buffer Because the nzsql command is line oriented, it is difficult to edit a complex, multiline SQL statement. Netezza sql supports query buffer that you can use to edit complex and multiline queries. Netezza nzsql Query Buffer Options \e — Edit…

When you use the Netezza nzsql command in interactive mode, there are many options that you can use. These options, known as Netezza nzsql internal slash options, are called with a backslash (\). Many of the internal slash options are the same as those available on the command line. In this article, we will check some of commonly used Netezza nzsql Internal Slash Options. Netezza nzsql Internal Slash Options Following are some commonly used Netezza nzsql internal slash commands: Command Description \? Lists the available internal slash commands. \h Lists…

Sometimes you may have to get the view or any object DDL directly from the Netezza database, in that case you might have noticed that query will not be in proper format. In this article, we will check Netezza SQL query formatter - nz_format with an example. Netezza SQL Query formatter - nz_format You can use the nz_format script functionality to format the Netezza SQL query which is not in proper format. Script will generate the formatted SQL if you pass raw query in form of file or standard input.…

If you are working on the huge data warehouse and that requires to create thousands of dimension and fact tables in hundreds of databases. You may want search for existence of particular table in hundreds of databases available in Netezza data warehouse appliance, this manual process is time consuming. In this article, we will discuss on Netezza find Database Objects to search the objects. Netezza find Database Objects – nz_find_object Luckily, IBM has provided a script nz_find_object, that can be used to find the objects in Netezza data warehouse appliance.…