View Incident Report

Improvement

Requested By: Suat Demirkiran
Requested On: 11/15/2008
For: Version 4.27 Build 1

# 2879 Need to Improve the Performance of Left Outer Join Conditions that Only Filter Rows

LEFT OUTER JOIN works very slow (10 times slower) when more than one fields are in join. Adding second contion (AND b.SaleDate>='2007-01-01') makes slower the query. Although SaleDate is indexed, it works like there is no index.

SELECT a.CustNo, b.OrderNo
FROM Customer a LEFT OUTER JOIN Orders b ON
(a.Custno=b.Custno AND b.SaleDate>='2007-01-01')

Resolution

Improvement Implemented on 11/26/2008 in version 4.27 build 2

Products Affected

DBISAM Additional Software and Utilities
DBISAM ODBC Client-Server
DBISAM ODBC Client-Server with Source
DBISAM ODBC Standard
DBISAM ODBC Standard with Source
DBISAM ODBC Trial
DBISAM VCL Client-Server
DBISAM VCL Client-Server with Source
DBISAM VCL Standard
DBISAM VCL Standard with Source
DBISAM VCL Trial

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