In this article, inspired from his presentation in IDUG EMEA 2019, Pawel Hryb talks on possibilities and strategies when doing complex SQL tuning in Db2 for z/OS: Where to begin, how to dissect a complex query, sources of information to try and how to proceed when you need a deeper investigation.
Este artículo provee conocimiento necesario y ofrece la base y al mismo tiempo el aspecto más importante sobre optimización de queries, es decir, estimar cardinalidad, o bien, estimar el número de registros que fluyen a través de las varias operaciones de la ejecución del plan de un query.
In Part 1, I talked about some of the first steps that a developer should go through when it comes to tuning queries. In this article, I will go through the initial steps in evaluating a SQL query using the Db2 explain output.
IBM® Data Server Manager is an integrated database management tools platform. In this article, learn how to use the Query Tuning functionality that is included with the Base edition of DSM at no additional charge to tune the queries running in your DB2® for z/OS® environment.
By now, most DB2 for LUW users have probably heard about the release of DB2 11.1 that became available in June of this year. In this article I’d like to provide more information on some performance optimizations in DB2 11.1 that will benefit queries accessing both row and column-organized tables.