Why you need current db2 runstats inside tech talk. Appendix h reorganizing the db2 catalog p rior to db2 v4, it was not possible to reorganize the table spaces in the db2 catalog and db2 directory because of the internal hash and link structures built into these databases. Runstats utility option has been added to reset statistics profiles. Runstats is a db2 utility that captures detailed information about the db2 objects, tables, indexes, etc.
Below are links to download idug db2 tech conference presentations. Please let me know what are the jobs i have to schedule in db to improve the db performance and the frequency of jobs. It is important therefore to collect a good base of statistics to give the optimizer a fighting chance. Db2 records these statistics in the db2 catalog and uses them to select access paths to data during the bind process. We do this to attempt to get predictable access paths across environments. Bryan smith, ibm db2 runstats utility and realtime statistics b05 details. Lies, damn lies, and statistics software engineering. I tell them for db2 applications, executing runstats is a good place to start. This document lists ibm db2 commands that are recommended for regular. We have a user, that runs an etl process for which one of the etl steps should have a runstats step on a spesific. The optimizer uses these statistics to determine access paths to the data.
Schedule runstat and reorg level 1, not scorable, 8, 9, 9. This utility will report all tables with data changes since the last runstats. Should the test runstats reflect the actual data in the test tables, or. Db2 udb product management ibm 30 jun 2006 learn skills that help you to properly manage your db2 database servers. It can also help move data that is related closer to each other for more efficient access especially true in the case of a cluster index.
Copying db2 runstats from one subsystem to another nancy perkinson. The runstats command updates statistics in the system catalog about the characteristics of a table, associated indexes, or statistical views. Reorg shrlevel reference catalog tables with links. How to run reorg, reorgchk and runstat on all tables in a.
Db2 v9 zos when to do initial runstats for new table. Common db2 for zos runstats collection mistakes the. For db2 v9, its ok to set it to unlimited or some high value. Before using this information and the product it supports, read the information in notices on.
Automated statistics collection in db2 udb citeseerx. When the runstats command is run on a table with the with distribution clause, the following apply to the collection of distribution statistics on a. From the db2 command line, execute the runstats command with. Fixed a few cosmetic problems that were bugging me.
Execute runstats in a stored procedure db2 database. The runstats utility updates statistics in the system catalog tables to help with the query optimization process. Syscomments on all columns and sampled detailed indexes all allow write access db20000i the runstats command completed successfully. Is it possible to have statistics on temporary tables. The db2 runstats utility collects the statistics and populates the. Db2 l db2 v9 zos when to do initial runstats for new table definition we have situations where the application developers request new tables that will be used to capture audit information and so will be populated over time as opposed to.
Change it, restart the instance and then retry the runstats. Before you run the runstats command, the database must contain data, and at. Can any one helpme dynamicailly reorg and runstat all tables of a particular schems. In db2 v9, there is no such option to run runstats schema vise or for complete database.
Open a ticket and download fixes at the ibm support portal find a technical. When should the db2 catalog and directory be reorganized. This would seem to be 99% clustered because 6 is the only value out of sequence. The runstats utility db2 developers guide 5th edition. How to use the runstats, reorg, reorgchk, and rebindutilities, and. Db2 estimator, available via web download for db2 v8, will not be provided for db2 v9 for zos. Without these statistics, the database manager could make a decision that would adversely affect the performance of an sql statement. Ibm db2 for zos utilities is leading the trend towards autonomics.
The runstats utility collects statistical information for db2 tables, table spaces, partitions, indexes. Problem conclusion reorg index db2 v8 and v9 and runstats v8 with dpsi processing, have been modified to check for the utprint data set prior to querying how it is allocated. Db2 uses this data when trying to determine the best access path for getting the data requested by the sql. If you do not set the parameters, a default of 200 is used. The intent of this ibm redpaper publication is to help db2 database administrators, db2 system programmers, and anyone who runs db2 for zos utilities implement best practices.
During the last couple of versions of db2 for zos, and through the maintenance stream, new features and enhancements have been delivered to further improve the performance and functionality of the db2 utilities. Instead, ibm optimization service center for db2 for zos, part of the nocharge ibm db2 accessories suite for zos 5655r14, extends visual. Bryan paulsen, best idug 2007 north america speaker. For those readers not yet using db2 v8, dstats can be downloaded. So,can we execute runstats from a stored procedure. Collecting catalog statistics ibm knowledge center. The db2 optimizer exploits the catalog information to choose an access path for a given sql statement, and runstats is what populates the catalog. So the processor, disk, memory, and database are all faster. I am looking for a better way to tell when runstats is needed. I tried 3 different ways to run runstats on a dgtt.
Reorganizing the db2 catalog and directory be reorganized. Update the db2 catalog with only db2 optimizer statistics. Db2 provide multiple tools and utilities for the maintenance, with these tools and utilities, its more convenient for dba to manage the db2 database. In preliminary testing, my reorg runs about 25% faster than on the old machine, but runstats runs 50% to 70% slower. Visual explain for db2 for zos, available via web download for db2 v8, will not be provided for db2 9. The intent of this paper is not to replicate the db2 utilities reference guide or the db2 installation guide. Progress indicators for reorg indexes and runstats. If this is aix, check user data limit of the instance owner id. But for db2 v4 and later releases, you can expediently reorga. These characteristics include number of records, number of pages, and average record length. There is a neverending argument concerning what should be reflected by the runstats in a test db2 subsystem. Basically i am asking if anyone has a method that allows runstats on spesific tables only, without giving dbadm or higher.
Hi, we want to execute runstats for all database tables in one go. Statistics collection on xmltype columns is governed by two db2 registry variables. Found out that ibm had removed the udb from the db2 product name, so i did the same. This keyword enables the optimizer to select the best access path. How to find reorgrunstats date hello all, i would like to know to how to find the date of last reorg runstats performed on any specific tabletablespace in db2 v8.
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