Re: enq: tx - contention on selects
From: Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk>
Date: Sat, 20 Sep 2008 15:12:48 +0100
Message-ID: <3tydnR-OtehDmUjVnZ2dnUVZ8tbinZ2d@bt.com>
Date: Sat, 20 Sep 2008 15:12:48 +0100
Message-ID: <3tydnR-OtehDmUjVnZ2dnUVZ8tbinZ2d@bt.com>
For more notes on Srivenu's comment, here's a note I wrote a few years back. Oracle changed the handling of distibributed transactions around 9.2.0.5 to deal with this issue in the case of XA processing, but the issue still exists for pure Oracle activity across database links.
Your select can wait for another transaction if that transaction is between the "prepare" and "commit" of a two-phase commit.
-- Regards Jonathan Lewis http://jonathanlewis.wordpress.com Author: Cost Based Oracle: Fundamentals http://www.jlcomp.demon.co.uk/cbo_book/ind_book.html The Co-operative Oracle Users' FAQ http://www.jlcomp.demon.co.uk/faq/ind_faq.htmlReceived on Sat Sep 20 2008 - 09:12:48 CDT