How does the Informix SQL Optimizer choose which index or table or access method to use when running your SQL? This presentation will focus on how to view and understand the SQL Explain plan to see how your SQL is executed. The SQL Explain plan will provide times for each step in your process.
This presentation will focus on Best Practices for Informix database indexes. Every table should have at least one index, and managing indexes is an integral part of a DBA's task and time. Indexing is one method to optimize the performance of a database by reducing the number of disk reads when a query is executed. An index is a structure which is used to locate and access a row in a database table quickly. Indexes are used to enforce uniqueness, primary, and foreign keys and constraints. Indexes can also be a source of problems in a database and may slow performance down when misused.
Informix includes many Advanced SQL OnLine Analytical Processing (OLAP) functions that are rarely used, and we will demonstrate how to take advantage of them. OLAP is Business Intelligence queries that allow users to perform reporting for sales, marketing, inventory control, business processes, and many other functions. Typically it would require a multi-dimensional database. SQL OLAP functions allow you to roll-up, roll-down and slice and dice your data. We will demonstrate examples of Window Partitioning of data (before and after group by), Ranking, using row numbers, and before and after rows using ANSI SQL-99 standards, known as the Elementary OLAP package.
How do you capture the cost of SQL statements and activity on your database server. We will take a look at SQL Trace, and the Sysmaster tables that enable you to save and analyze the costs of your SQL.
This session will cover some of the basics of Informix Tuning, with a focus on monitoring and tuning of queries. Some of the areas that will be covered include: Identifying long running queries, Explain plans, Optimizer directives, Monitoring the buffer pool usage, Checking statistics, and Finding busy tables
Art Kagel, is an Independent consultant and IIUG Board Member, presented on programming, concurrency, and tuning applications against Informix. This is an update to the presentation Art did at our last Washington Area Informix User Group Meeting. (Note: there are a few problems with the sound, I tried to fix it as best as I could)