Comments on: Dynamic_plan_table, x$kqlfxpl and extreme library cache latch contention http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/ Discussions about Oracle performance tuning, RAC, Oracle internal & E-business suite. Mon, 17 Jun 2013 02:28:12 +0000 hourly 1 http://wordpress.com/ By: Log Buffer #140: A Carnival of the Vanities for DBAs | WORDPRESS EXTENSIONS-PLUGINS-THEMES-TEMPLATES http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-260 Mon, 23 Mar 2009 08:40:49 +0000 http://orainternals.wordpress.com/?p=384#comment-260 [...] Shamsudeen also was sleuthing—into dynamic_plan_table, x$kqlfxpl and extreme library cache latch contention. Dion Cho, the Oracle Performance Storyteller, responded with an item about a similar experience of [...]

]]> By: orainternals http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-257 Fri, 20 Mar 2009 20:11:26 +0000 http://orainternals.wordpress.com/?p=384#comment-257 Tanel
Thanks for visiting my blog. Your tools are excellent and thanks for sharing them.
Cheers
Riyaj

]]> By: Another LatchProfX use case | Tanel Poder's blog: Core IT for Geeks and Pros http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-256 Fri, 20 Mar 2009 19:35:51 +0000 http://orainternals.wordpress.com/?p=384#comment-256 [...] Shamsudeen wrote an excellent article about systematic latch contention [...]

]]> By: Tanel Poder http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-255 Fri, 20 Mar 2009 19:18:56 +0000 http://orainternals.wordpress.com/?p=384#comment-255 Hi Riyaj,

Very cool article! (and using the right approach too ;)

I’m happy to see that people find my tools useful!

Btw, you probably know this (but I didn’t see it mentioned) that you can see the function names responsible for these latch holds from LatchProfX output too, also the latch hold mode if dealing with a shared latch:


SQL> @latchprofx sid,name,laddr,ksllwnam,ksllwlbl,hmode 159 % 100000

-- LatchProfX 1.08 by Tanel Poder ( http://www.tanelpoder.com )

SID NAME LADDR KSLLWNAM KSLLWLBL HMODE Held Gets Held % Held ms Avg hold ms
---- -------------- ---------------- --------- --------- ---------- ------ ----- ------- -------- -----------
159 library cache 00000003A93513E0 kglic child exclusive 10044 9314 10.04 301.320 .032
159 library cache 00000003A9351340 kglic child exclusive 9895 8458 9.90 296.850 .035
159 library cache 00000003A9351660 kglic child exclusive 9761 8440 9.76 292.830 .035
159 library cache 00000003A9351700 kglic child exclusive 9737 8924 9.74 292.110 .033
159 library cache 00000003A9351480 kglic child exclusive 8999 7765 9.00 269.970 .035
159 library cache 00000003A93515C0 kglic child exclusive 8553 7832 8.55 256.590 .033
159 library cache 00000003A9351520 kglic child exclusive 6852 6828 6.85 205.560 .030

7 rows selected.

]]> By: Pythian Group - Blog http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-254 Fri, 20 Mar 2009 16:40:45 +0000 http://orainternals.wordpress.com/?p=384#comment-254 [...] Shamsudeen also was sleuthing—into dynamic_plan_table, x$kqlfxpl and extreme library cache latch contention. Dion Cho, the Oracle Performance Storyteller, responded with an item about a similar experience of [...]

]]> By: orainternals http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-249 Tue, 17 Mar 2009 15:51:40 +0000 http://orainternals.wordpress.com/?p=384#comment-249 Thanks Martin. It was nice to meet you at hotsos 2009 dinner.

Cheers
Riyaj

]]> By: Martin Decker http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-248 Tue, 17 Mar 2009 15:27:17 +0000 http://orainternals.wordpress.com/?p=384#comment-248 Hi Riyaj,

great analysis! I have used the technique before (http://www.ora-solutions.net/web/2008/10/19/formatted-sql-plan-display-in-oracle-9i/) but was not aware of its drawbacks.

Regards,
Martin

]]> By: Heavy reads on the library cache related v$ views. « Dion Cho - Oracle Performance Storyteller http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-245 Mon, 16 Mar 2009 09:07:24 +0000 http://orainternals.wordpress.com/?p=384#comment-245 [...] leave a comment » Riyaji posted a very interesting case here. [...]

]]> By: Dion Cho http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-243 Mon, 16 Mar 2009 00:55:11 +0000 http://orainternals.wordpress.com/?p=384#comment-243 Very interesting case.
Thanks for sharing it.

]]> By: orainternals http://orainternals.wordpress.com/2009/03/13/dynamic_plan_table-xkqlfxpl-and-extreme-library-cache-latch-contention/#comment-241 Sun, 15 Mar 2009 17:41:23 +0000 http://orainternals.wordpress.com/?p=384#comment-241 Hi Radino
Thanks for visiting this blog. Yes, use of context variable could have been better than recreating view.
Still, my preference is to resolve root cause so that optimizer can choose first_rows.
Cheers
Riyaj

]]>