After Upgrade to 12c from 11g, Query Uses Nested Loop Instead Of Merge Join, Causing Slow Performance

After Upgrade to 12c from 11g, Query Uses Nested Loop Instead Of Merge Join, Causing Slow Performance (Doc ID 2250039.1)

Last updated on APRIL 05, 2017

Applies to:

Oracle Database - Enterprise Edition - Version 12.1.0.2 and later
Information in this document applies to any platform.

After upgrading our database from 11.2.0.4 to 12.1.0.2, sql is not using merge join anymore, instead it uses nested loop and the script runs forever

Upgraded from 11.2.0.4 to 12.1.0.2

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