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Debugging/Tuning Queries via iSeries Navigator Tom McKinley Mac2@us.ibm.com. Tour . What’s info is available System Monitoring Collection Services Work Management Table Show Indexes Index Advisor (DB, Schema or table level) BETA ONLY, removed from presentation. Stats .
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Debugging/Tuning Queries via iSeries NavigatorTom McKinleyMac2@us.ibm.com
Tour • What’s info is available • System Monitoring • Collection Services • Work Management • Table • Show Indexes • Index Advisor (DB, Schema or table level) BETA ONLY, removed from presentation. • Stats
Other sources of Info • DB2 for iSeries Web Site • http://www-03.ibm.com/servers/eserver/iseries/db2/ • Monitor queries • http://www-03.ibm.com/servers/eserver/iseries/db2/dbmonqrys.htm • White papers • http://www-03.ibm.com/servers/eserver/iseries/db2/awp.html • SQL performance and query optimization guide (Info Center) • Common, Tech Conferences… • Query Performance tuning workshop • http://www-03.ibm.com/servers/eserver/iseries/service/igs/db2performance.html
Summary • Many things affect query plans • Try to understand the access methods • Learn the tools • Size matters • “Bad Performance does not scale”. • You need to collect info before you make changes to help understand what changed and the impact of that change. • Don’t only focus on Runtime. Look for resource hogs, or for queries that are run frequently • Good indexing strategy in some cases is critical