This article provides an overview of the major object groups in Netezza, including Users, User Groups, Tables, Views, Materialized Views, Synonyms, Databases, Procedures, and User Defined Functions. If you are familiar with other relational database management systems, you'll notice that there are no indexes, bufferpools, or tablespaces to manage in Netezza.
The appliance comes preconfigured with three user ids that cannot be modified or deleted from the system. These are:
By default, Netezza comes with a database group called public. All database users created in the system are automatically added as members of this group and cannot be removed from it.
Netezza comes with two databases: System and a model database, both owned by the Admin user. The system database consists of objects like tables, views, synonyms, functions, and procedures. The system database is primarily used to catalog all user database and user object details, which will be utilized by the host when parsing, validating, and creating execution code for queries from the users.
Netezza is a high-performance data warehouse appliance that provides fast analytic processing for large datasets. Understanding its database structure, specifically tables and other database objects, can help you optimize your queries and make the most of this powerful tool.
A Netezza database consists of one or more schemas. A schema is a logical container for tables, views, and other database objects.
Tables are the primary data structures in a Netezza database. They store the actual data that you query. Here's an example of creating a simple table:
CREATE TABLE my_table (
id INTEGER,
name VARCHAR(255)
);
A view is a virtual table based on the result-set of an SQL query. Views can be used to improve application and database portability, enhance table independence, simplify large and complex SELECT statements, reduce data redundancy, and restrict access to base tables.
A sequence is a database object that generates numeric values according to user-defined rules. Sequences are often used for automatically generating primary keys or other auto-incrementing columns in tables.
An index is a data structure that improves the speed of data retrieval operations on a table, at the cost of slower write operations. Indexes can be created using one or more columns of a table and are used to quickly locate rows meeting certain conditions.
Understanding Netezza databases, tables, and other database objects is crucial for optimizing your queries and leveraging the power of this high-performance data warehouse appliance. Remember to use views to simplify complex queries, sequences for auto-incrementing columns, indexes to speed up data retrieval, and always design your schema with efficiency in mind.