Re: what's "enq:TX - contention
- From: "Jonathan Lewis" <jonathan@xxxxxxxxxxxxxxxxxx>
- To: <oracle-l@xxxxxxxxxxxxx>
- Date: Thu, 29 Nov 2007 21:43:40 -0000
Several options, for example: session 1 - execute some dml without commit session 2 - alter tablespace X read only;The tablespace cannot go read only until all current transactions commit - so session 2 picks the oldest
current transaction and waits on it using a TX mode 4. The wait in 10g will show as "TX - contention" 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.html ----- Original Message ----- > Date: Thu, 29 Nov 2007 16:05:00 +0800
From: "Eagle Fan" <eagle.f@xxxxxxxxx> Subject: Re: what's "enq:TX - contention" any comments? Thanks On Nov 27, 2007 12:19 AM, Eagle Fan <eagle.f@xxxxxxxxx> wrote:hi: In 10g, oracle has four TX wait events: 1. enq:TX - row lock contention 2. enq:TX - index contention 3. enq:TX - ITL 4. enq:TX - contention I know the first three ones' meanings. But what does the last one "enq:TX - contention" mean? I know it means other TX enqueue types. But what's the *other* TX enqueues? Could anybody give me some examples? We have insert sql causes this TX contention. I searched metalink and oracle-l, but most doc/threads are discussing the first three ones. Thanks a lot.