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Joins in Queries [message #170341] Wed, 03 May 2006 07:17 Go to next message
kumarsz
Messages: 180
Registered: March 2005
Location: canada
Senior Member
Hi,
Regarding -> Oracle 9i Release 2
I understand that statistics and data in the tables decides which join (Sort Merge or Nested Loop or Hash) will be performed on queries involving joins.
Also for getting first few rows faster Nested Loop join is better.
however in all other cases which join is better than the other considering CBO and statistics taken properly (including histograms) ?
If that is not the case why we may use hints for NL or MERGE etc.

Please suggest

Thanks in Advance,
Pratap
Re: Joins in Queries [message #170454 is a reply to message #170341] Wed, 03 May 2006 22:34 Go to previous message
rleishman
Messages: 3728
Registered: October 2005
Location: Melbourne, Australia
Senior Member
You should read the section on Joins in the Performance Tuning Manual

These are my notes on Joins.

Ross Leishman
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