Tuning de DB2 pour améliorer la rapidité sur un gros volume de donnée – Partie 2: Governor « Lost somewhere… L’utilitaire governor Cette application permet de surveiller le comportement des applications qui sont connectées à la base et changer ce comportement suivant comment on configure le governor.
Il est constitué d’une interface et d’un agent par instance et par partition. Bien entendu, cette application a un cout en terme de ressource et il faut donc éviter de la lancer trop souvent pour éviter une utilisation trop grande des ressources par celle-ci. Chaque agent va relever des stastiques à propos des applications et va comparer ces informations avec les régles contenues dans le governor. Par exemple, une régle peut être que si une application utilise trop de ressources, on va la déconnecter ou lui changer sa priorité. Avant de lancer l’application, il faut penser à créer les régles. Ecrire un fichier de configuration de régles consiste à créer un nouveau fichier texte (par exemple, govrulesdb_name).
Interval 1; dbname db_name; account 30; 6 champs sont disponibles pour créer les régles: Www.quser.org/Docs/Db2_Indexing_Tips_Tricks_MIPS.pdf. Www.common-romandie.ch/files/pre_2011_05_03_4_les_bases_de_loptimisation_sql_a.pdf. Top 10 Tips for Tuning DB2 Part 1. ShareThis We all agree that there is no one tuning that can solve all of your database performance issues.
But at least by following the top 10 DB2 performance tips listed below, and optimized for DB2 version 9.5 and above, you will at least achieve noticeable improvement right away, and it does not break your IT budget -- these tips are free! To help DB2 DBAs avoid performance fires and achieve high performance on their own, the following tips summarized a troubleshooting process for performance bottlenecks that is in your database. These 10 tips apply best for OLTP applications using DB2 LUW. Part 1 1. Part 2 5. Part 3 8. Tip #1 Optimize bufferpool hit ratios bufferpool hit ratio calculation: (pool_data_l_reads - (pool_data_p_reads - pool_async_data_reads))/ pool_data_l_reads - Great values: 95% for index, 90% for data - Good values: 80-90% for index, 75-85% for data To query bufferpool hit ratio, first turn ON the default bufferpool monitoring switch: Next Page.
Ibm db2 database tuning. ShareThis The DB2 runstats command updates statistics that profile the physical characteristics of a database table, along with its associated indexes.
Dynamic SQL statements generated by your app code will automatically use these updated statistics, but static SQL statements built inside a database require the DB2 rbind command be run as well. Execution of runstats/rbind should be done on a regular basis as part of regular database maintenance. As your databases grow and change over time, recalculating table statistics is critical to improving database performance and should be done regularly (manually using scripts below or using a cron job). Along with runstats/rbind, the DB2 reorgchk command should also be run to check to see if a reorganization of certain tables and/or indexes may be warranted. Here we list the common tuning parameters and their corresponding values used in large DB2 setups (for Enterprise data volume and traffic).
Top 10 DB2 performance tips. IBM Data magazine: It's all about the data. Ibm db2 database tuning.