Db2 udb for linux, unix, and windows administration oracle docs. Profile table and can be modified through the runstats command and queried through sql. It is highly recommended that you use the runstats command to collect current statistics on tables and. Execute runstats on all the db2 tables partitoned table spaces always have 1 table each. I am running runstats command to update the runtime statistics of a particular table called customer in db2. When you have a bad access path that you have discovered through sql monitoring, or telephones ringing, you can very simply reset the db2 catalog optimizerrelevant statistics to a point in time where the sql access path was better, thus rescuing you from the perils of bad access. After running the command, if i look into the syscoldist table, the information for column cid is populated correctly. Use the following task to execute the runstats command on ibm db2 database, or see your database administrator to have the command executed. Db2 udb for linux, unix, and windows administration.
I once administered a database that was dynamic and i didnt want to take a chance on forgetting new tables so i created a set of scripts that generated the. Silver, analyze and runstats are not sql statements, but db2 commands the first are explained in the sql reference and the latter in the command reference. Runstats is a db2 utility that captures detailed information about the db2 objects, tables, indexes, etc. Db2 uses a metric on how much data in a table has changed to decide if runstats are needed, and ive seen it make some major misses, even with db2 10. It is assumed that the index contains the set of columns that are critical to the table and are most. Do you already have some code for db2 in dbeaver somewhere. New features in db2 9 for luw auto reorg sap blogs. Run runstats in the db2 udb database stage in the after. The optimizer uses these statistics to determine access paths to the data. Runstats rescue gathers all the db2 optimizerrelevant statistics and saves them away on a regular basis.
Automated statistics collection in db2 udb vldb endowment. Check the db2 command reference pdf and pre v8 html or when using the v8 html doc. Shell script to automate runstats in db2 posted on february 15, 2009 by rpillai had some free time today, so wrote a small script that will automatically create a runstats script for all the tables for all the databases in an instance. Monitoring the progress of runstats operations ibm knowledge. The function is sqlustat look in the api reference for all the details. If you choose rebuild, the dictionary that is required for the row compression feature is rebuild during reorg. Sep 29, 2006 the next choice is related to the new features in db2 udb v9 part 4. Embers best practices for runstats and reorgs datageek.
How to run reorg, reorgchk and runstat on all tables in a database queries to execute reorg, reorgchk and runstat on all tables in a database write the following scripts in a. The db2 zos subsystem contains information for establishing connections with remote subsystems in a set of catalog tables called communication database cdb. Reorg is used to help db2 point to accurate data ie, indexes should become aware of fresh data and no longer include deleted data, as well as collapse empty page space created by deletion of data andor indexes. You cannot call commands through jdbc only sql statements. You should type the command exactly as shown in a window whose title is db2 clp. Db2 maintenance script runstats, reorg posted on april 11, 20 march 3, 2017 by daharveyjr i had a local copy of a websphere commerce database that was performing horribly, and i decided to create a script that would retrieve a list of all available tables for all nonsystem schemas, and perform a runstats and reorg for those tables. Apr 11, 20 db2 maintenance script runstats, reorg posted on april 11, 20 march 3, 2017 by daharveyjr i had a local copy of a websphere commerce database that was performing horribly, and i decided to create a script that would retrieve a list of all available tables for all nonsystem schemas, and perform a runstats and reorg for those tables. For db2udb and db2 zos you can also run utility control statements such as runstats, load etc. In online reorg all application can connect to database. So using reorg command is ran, it physically deletes the record from db. When running db2 commands shown in this document in a db2 clp window, db2 commands start with the command db2. I tell them for db2 applications, executing runstats is a good place to start. This task is a step in process of performing an incremental upgrade of the siebel database from siebel crm version 8. Db2 uses this data when trying to determine the best access path for getting the data requested by the sql.
For example, when this document shows the following db2 command. These are not normal statements so cannot be run through a normal sql interface. With the myschema being the schema you want to run runstat on all of its tables, you can issue following commands to have a script file. The customer has two columns cid integer and info xml column. How to execute runstats on all the db2 tables present in all table spaces in a. Updates statistics about the physical characteristics of a table and the associated indexes. Why you need current db2 runstats inside tech talk. The schema is the user name under which the table was created. Jun, 2016 the db2 optimizer exploits the catalog information to choose an access path for a given sql statement, and runstats is what populates the catalog. The runstats command updates statistics in the system catalog about the characteristics of a table, associated indexes, or statistical views. First connect to the database, then issue the db2 runstats on table.
With db2, you need to call a function, rather than issue an sql statement. May 19, 2014 runstats is a db2 utility that captures detailed information about the db2 objects, tables, indexes, etc. This topic describes eim tuning tips for the ibm db2 udb database platform. Use this options page to define parameters for the runstats utility that toad invokes whenever it creates or rebuilds db2 for zos tables, tablespaces, or indexes during object management see the ibm db2 for zos utility guide and reference for more information about these options notes. This way, you can run the runstats command more often. Common db2 for zos runstats collection mistakes the. Run runstats in the db2 udb database stage in the after section.
Statistics collection on xml type columns is governed by two db2 database system registry values. Aug 27, 2012 with the myschema being the schema you want to run runstat on all of its tables, you can issue following commands to have a script file. It is important therefore to collect a good base of statistics to give the optimizer a fighting chance. 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. I am creating a server job using a db2 udb database stage. Command parameters table tablename the table on which to update statistics. Runstats is a clp command and is not sql statement. But there is nothing filled for the info xml column. The db2 passwords for connecting to database are encrypted. In same way, you can issue reorg command for all tables in a schema using the following line. Compare db2 for zos and db2 for linux, unix, and windows. The location of db2 zos is defined when the db2 subsystem is installed, which you can find by executing the dis ddf command on the db2 zos server, as shown in listing 3.
Sep 01, 2011 the location of db2 zos is defined when the db2 subsystem is installed, which you can find by executing the dis ddf command on the db2 zos server, as shown in listing 3. Executing the runstats command on ibm db2 database during. Db2 already offers a method of doing this but in my experience short but quite varied, and on the recommendations of an outside consultant with much expertise we decided that using the db2 health monitor to monitor the tables and decide itself when to carry out the runstats on tables was not turning out to be the best idea. Ibms db2 connect provides connectivity to a db2 luw database server and other db2 udb family servers as well as sql support. These characteristics include number of records, number of pages, and average record length. For example, if you want to download a db2 server for 32bit linux or unix. The last time a runstats command was executed on a table along with its associated statistics profile can be found in the syscat. Db2 udb consultant ibm 20 may 2003 this tutorial introduces utilities provided by db2 servers for data movement and maintenance. Reference commands command line processor clp hope this helps. A statistic profile associates a table and its runstats command definition together with its definition in the catalog. There are a ton of options on the runstats command. Feb, 2011 db2 already offers a method of doing this but in my experience short but quite varied, and on the recommendations of an outside consultant with much expertise we decided that using the db2 health monitor to monitor the tables and decide itself when to carry out the runstats on tables was not turning out to be the best idea. Db2 runstats not working for xml columns server fault. If time to collect statistics is limited and the effort to tailor the runstats command on a tablebytable basis is a major issue, consider collecting statistics for the key columns only.
After the process inserts, i would like to run a runstats command in the after section of the query. Front cover microsoft sql server to ibm db2 udb conversion. Runstats profiles are stored in the system catalog in the sysstat. To gather the runstats information refer to the sql listed in figure 2. Sql issued from the command center can be stored as scripts and retrieved for later use from the script center. The point of an optimizer is to enhance performance. This could lead into a better compression rate, but costs additional time. The next choice is related to the new features in db2 udb v9 part 4. Use this command after running the runstats utility to revalidate all packages in the database. This is the fifth tutorial in a series of six tutorials to help you prepare for the db2 v8.
The db2 optimizer exploits the catalog information to choose an access path for a given sql statement, and runstats is what populates the catalog. It is important therefore to collect a good base of statistics to give the optimizer a fighting chance of choosing wellperforming access paths for your sql. How to run reorg, reorgchk and runstat on all tables in a. Open a dos window, then enter db2cmd to start a db2 clp window. On each db2 for zos subsystem on which you want to. Gerald you can create a db2 stored procedure written in c that calls db2runstats from db2 administrative api. How to execute runstats on all the db2 tables present in all table spaces in a database at once. Microsoft sql server to ibm db2 udb conversion guide wheijen chen alain fisher stefan hummel shailendra kishore wei bin teah ted wasserman complete guide to convert from microsoft sql server to ibm db2 udb application enrichment through advanced db2 udb features application conversion with detailed examples front cover. Thus the only measure of the quality of an optimizer, much like the only measure of performance of an index, is. Often ill let automatic stats run, but then have a weekly full scripted stats or have a script that looks for tables with old runstats and only does runstats on them. How to run a reorg and runstats online how to run reorg, reorgchk and runstat on all tables in a database how to check when was executed the last runstats in a specific table. Catalog database it gives more info on particular command quit commnad.
In addition to the information available here and elsewhere on siebel bookshelf, ibm have published a redbook, siebel 7. It can also help move data that is related closer to each other for more efficient access especially true in the case of a. Common db2 for zos runstats collection mistakes the world. The tried and true way to collect statistics in a db2 database is using a series runstats commands in a scrip that is run at some regular interval, say every weekend. Db2 udb command window or the graphical command center.
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