A poorly written query can return too much data, making the results unusable. These types of queries often produce meaningless results, are very resource-intensive, and reduce the performance of your system.
Using filters, you can protect your system from poorly written queries by preventing these queries from even starting to execute. Rejecting bad queries also helps educate the users to write better and more specific queries, which can reduce the number of bad queries over time.
For information about how to write good queries, refer to Teradata’s SQL documentation.
For example, you can prevent the following queries from executing:
- Queries that return too many rows
- Queries that take too long to run
- Queries that scan very large tables
The following is an overview of the process:
Scenario assumptions
This scenario assumes you already have the following set up:
- Teradata Database version: 15.0
- Operating system: SLES 11
- System: PROD1
- Ruleset: BadQueries