
	Home > Ask the AS/400 Experts > DB2/400 and DB2 UDB Questions & Answers > Possible to improve SQL query speed?

Ask The iSeries 400 Expert: Questions & Answers

EMAIL THIS

Possible to improve SQL query speed?

EXPERT RESPONSE FROM: Kent Milligan

		Pose a Question

		Other iSeries 400 Categories

		Meet all iSeries 400 Experts
		Become an Expert for this site

Digg This!

StumbleUpon

Del.icio.us

QUESTION POSED ON: 31 July 2003
SQL query is faster at second run because files are already loaded into memory and thus there is no I/O.

How can I reinstate the first run condition for a query without IPLing my system? I'm at V5R2. I did try the CLRPOOL command and SETOBJACC, but didn't have any luck.

Any query interface on the iSeries (SQL, Query/400, OPNQRYF, etc) would have the same behavior of running faster on the second time if objects stay resident in memory.

Not sure why you don't think that SETOBJACC isn't working to clear objects, but that would be the preferred method over the CLRPOOL command. With SETOBJACC, you also need to remember to clear out any indexes or keyed logical files used by the query optimizer in the implementation of your query.

Digg This!

StumbleUpon

Del.icio.us

RELATED CONTENT

	DB2 UDB (universal databases)
	Oracle boasts 11g on SPARC is faster than IBM DB2 on Power 595
	When is the YES option for 'reuse deleted files' function the best choice?
	Monitoring members 'stuck' within a physical file on an EDI system
	Developing tables in a parent-child relationship in DB2
	SQL server error message -321
	Creating a host variable of the 'where in' statement in SQL
	Choose which column names are returned via ODBC when working with DB2 files
	Access path and an open data path differences
	Database performance comparisons on IBM i
	Implement variables in SQL when creating an alias
	DB2 UDB (universal databases) Research

iSeries SQL commands and statements

Enhancing RPG with external SQL stored procedures

Tracking data changes on IBM i with triggers

Introduction to SQLRPGLE on IBM i: Making a report

Making the most of RPG data handling on IBM i

When is the YES option for 'reuse deleted files' function the best choice?

Monitoring members 'stuck' within a physical file on an EDI system

Creating a host variable of the 'where in' statement in SQL

SQL server error message -321

Choose which column names are returned via ODBC when working with DB2 files

Convert a numeric physical file to a character in SQL without leading zeros

iSeries SQL commands and statements Research

Oracle on iSeries

Oracle boasts 11g on SPARC is faster than IBM DB2 on Power 595

Debating DB2 versus Oracle

IBM steps up iSeries, pSeries overlap

Securing query definitions

New, undocumented Query function can boost your productivity

Get the system to recognize a date separator

Run multiple SQL statements

Populate a Lotus Notes database with iSeries data

Updating the 'VALUE' column using DB2/400

Inserting data into a table

RELATED RESOURCES

2020software.com, trial software downloads for accounting software, ERP software, CRM software and business software systems

Search Bitpipe.com for the latest white papers and business webcasts

Whatis.com, the online computer dictionary

Search and Browse the Expert Answer Center
Search and browse more than 25,000 question and answer pairs from more than 250 TechTarget industry experts.

Browse our Expert Advice
Operating Systems IT Management Networking Database	Security Servers and Storage Applications and Development Career Center

iSeries Networking - Printing, Remote Access, TCP/IP

SEARCH

TechTarget provides technology professionals with the information they need to perform their jobs - from developing strategy, to making cost-effective purchase decisions and managing their organizations' technology projects - with its network of technology-specific websites, events and online magazines.


TechTarget Corporate Web Site \| Media Kits \| Site Map All Rights Reserved, Copyright 1999 - 2009, TechTarget \| Read our Privacy Policy