hash join and nested loop join in an oltp query

From: <ryan.gaffuri_at_cox.net>
Date: Tue, 4 May 2004 14:43:13 -0400
Message-Id: <20040504184311.JMUB18641.lakermmtao05.cox.net@smtp.central.cox.net>

I Have seen some multi-table joins which return a small subset of records using hash joins. To test results, I hinted them to do nested loop joins and found response time to be alot slower and consistent gets to be much higher.

what types of cases make hash joins superior to nested loops? I see them alot in batch processing when I need to join most of the rows, but I am see them now when I return a small subset of rows.

has anyone experienced this?

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Received on Tue May 04 2004 - 13:40:35 CDT